Editor's Note: As the "nerve endings of the information age," sensors have penetrated every critical field of the socio-economic landscape. Since October 2025, China Electronics News has invited Guo Yuansheng, Deputy Director of the Science and Technology Committee of the Jiusan Society Central Committee and Executive Vice Chairman of the China Sensor and IoT Industry Alliance, to launch the "Guo Yuansheng Explains Sensors" column. Focusing on eight major fields and scenarios—power, major equipment, intelligent manufacturing, smart agriculture, smart healthcare and big health, smart home appliances and consumer electronics, urban security, and low-altitude economy—the column has published articles such as "Stationed at the Power Generation Side: Sensors Become the Cornerstone of Stable Operation in New Power Systems" and "Energy Storage Sensors Clarify Three Core Development Directions," receiving widespread attention and high praise from readers. This issue marks the second article in the consumer electronics sector, focusing on smart home sensors, elaborating on their application prospects, industrial status, and future recommendations to build industry consensus and promote industrial development.
The rapid development of smart homes has reshaped people's home living styles. As the core "sensing units" or "information interaction organs," sensors endow living spaces with the ability to perceive, analyze, and respond. From a hallway light automatically turning on, to the precise monitoring of an elderly person's sleep and breathing in the bedroom; from instant alarms for gas leaks in the kitchen, to the automatic adjustment of living room curtains—the realization of these smart scenarios relies on the coordinated operation of various sensors.
In recent years, given the accelerating aging process, elderly individuals living at home have more urgent demands for intelligence regarding family comfort and safety from three dimensions: physical space, functional dimensions, and service targets. Consequently, the demand for sensors in smart homes has naturally shown explosive growth. Industry data shows that in 2025, the global smart home sensor market size has exceeded 80 billion US dollars, with China accounting for over 30%, making it the fastest-growing country globally. Against this backdrop, an in-depth analysis of the types, application scenarios, functional values, and market trends of smart home sensors holds significant reference value for subsequent technological innovation and product implementation.
I. Current Development Status of Smart Home Sensors at Home and Abroad
Domestic Development Status: Policy-Driven + Enterprise Innovation, Building a Localized Industrial Ecosystem
The development of the domestic smart home sensor industry is inseparable from the dual driving forces of policy and market. In recent years, the state has successively introduced policies such as the "14th Five-Year Plan for Intelligent Manufacturing Development" and the "Action Plan for High-Quality Development of the Smart Home Industry," explicitly identifying sensors as a core link in the smart home industry chain for key support. On the one hand, financial investment in the R&D of core sensor technologies has been increased through new infrastructure projects; on the other hand, enterprises are encouraged to participate in the formulation of industry standards, promoting the deep integration of sensors with home appliances, security, health, and other fields. Data from the Ministry of Industry and Information Technology (MIIT) shows that in 2024, the proportion of R&D investment in domestic smart home sensors exceeded 15%, an increase of 8 percentage points from 2020, laying a solid foundation for technological breakthroughs.
At the enterprise level, leading brands have formed a layout model of "chips + unit modules + application scenarios." Huawei has launched a variety of smart sensors covering human presence, temperature and humidity, and light. Separately, Shenzhen Hi-Link Electronic's HLK-LD2410 human presence sensor, with a response speed of 0.1 seconds, a detection distance of 0-10 meters, and precise recognition of micro-movements (such as an elderly person slowly getting up), has become a benchmark product for home elderly care scenarios.
In addition to leading enterprises, a group of "Little Giant" enterprises specializing, refining, and differentiating have achieved breakthroughs in segmented fields. For example, sweat sensors that can detect lactic acid and electrolyte content through skin contact provide non-invasive blood glucose monitoring references for elderly diabetic patients; gas sensors using infrared spectroscopy analysis technology with a response time of less than 1 second have been included in the standard smart security equipment lists of gas companies in many regions.
Overseas Development Status: Deep Technological Cultivation + Global Layout, Leading the High-End Market
The overseas smart home sensor industry started early and holds advantages in core technologies and brand recognition, especially maintaining a leading position in the field of high-precision and high-stability sensors.
American enterprises focus on environmental monitoring and AI integration technologies. Honeywell's HPMA115S0 air quality sensor can simultaneously detect multiple indicators such as PM2.5, VOC, and carbon dioxide, with a detection accuracy of ±1μg/m³. Its built-in AI algorithm can automatically adjust the fresh air system according to user habits. This sensor has been widely used in American smart housing projects, with a market share of over 40%. Additionally, Apple integrates third-party sensors through its HomeKit ecosystem. Its self-developed U1 ultra-wideband (UWB) chip is applied to human positioning sensors, achieving centimeter-level positioning accuracy and supporting scenarios such as "automatically unlocking smart door locks when the user approaches and adjusting light brightness according to the user's position." It has currently achieved deep linkage with brands such as Yale locks and Philips lighting.
German enterprises stand out in the stability of security sensors. Bosch's infrared curtain sensor (ISW-ZPR1-WP13) adopts dual-element infrared detection technology, which can effectively filter out interference factors such as pets and light/shadow changes, with a false alarm rate of only 0.1%. It also features an IP65 waterproof rating and can operate stably in extreme environments from -30℃ to 50℃. This product has ranked first in the European smart security market for five consecutive years, with global sales exceeding 20 million units in 2024.
Japanese enterprises focus on the miniaturization and low power consumption of health monitoring sensors. Sony's micro blood oxygen sensor (CXD5603GG) is only 3mm×3mm in size, with power consumption as low as 10μA. It can be integrated into devices such as smartwatches and pillows to monitor the blood oxygen saturation of the elderly in real time, automatically triggering an alarm when the value drops below 90%. Panasonic's fecal analysis sensor analyzes indicators such as occult blood and bilirubin in excrement through a built-in spectrum detection module in the toilet. The data is synchronized to medical institutions to provide remote health management services for elderly patients with chronic diseases. Currently, its penetration rate in Japanese elderly care institutions has reached 60%.
Differences and Commonalities in Development at Home and Abroad
From the perspective of differences, domestic enterprises are better at rapid iteration and cost control based on local needs. For example, fall prevention sensors developed for home elderly care scenarios generally possess dual functions of voice alarms and mobile phone push notifications in China, and their prices are only 1/3 of similar foreign products. In contrast, foreign enterprises maintain technological barriers in core chips and algorithm R&D. For instance, signal processing chips from Texas Instruments (TI) in the US can improve detection accuracy by 40%. Currently, 30% of domestic high-end sensors still rely on imports.
From the perspective of commonalities, enterprises at home and abroad are both moving towards "multi-sensor integration + AI algorithm optimization." Both Huawei domestically and Apple overseas have launched sensor modules that integrate functions such as human perception, environmental monitoring, and health detection into a single module, reducing the complexity of device installation. Meanwhile, by collecting user data to train AI models, they enhance scenario adaptation capabilities, such as automatically adjusting the detection sensitivity of sensors according to the user's routine to avoid false triggers at night.
In addition, both domestic and overseas markets attach importance to the development of standardized protocols for sensors. China has formulated the "Technical Specification for Smart Home Sensor Interfaces" to unify the communication protocols between sensors and smart terminals. Overseas, there are the Zigbee Alliance and the Matter protocol, promoting the interconnection of sensors from different brands. By 2025, the proportion of domestic products supporting the Matter protocol has reached 55%, while this proportion exceeds 70% overseas. Standardization has become a critical trend in industry development.
II. Core Sensor Types and Technical Parameters
Environmental Sensors: Building a Home "Environmental Perception Network"
Environmental sensors are mainly used to monitor environmental parameters such as indoor temperature, humidity, light, and air quality, providing data support for the automatic adjustment of smart devices.
- Temperature and Humidity Sensors
Working Principle: Capacitive humidity sensing elements and thermistor temperature sensing elements are used to convert temperature and humidity changes into electrical signal outputs.
Core Technical Parameters: The measurement range is typically 0-50℃ for temperature (accuracy ±0.5℃) and 20%-90%RH for humidity (accuracy ±3%RH); response time ≤10s; power consumption is generally below 10mW.
Representative Products: Xiaomi Temperature and Humidity Sensor 2nd Generation, using the SHT30 chip, supports Bluetooth 5.0 transmission, and can link with air conditioners and humidifiers, automatically triggering the humidifier when humidity drops below 40%RH; Siemens QAA2010 temperature and humidity sensor, featuring an IP54 waterproof rating, is suitable for humid environments such as kitchens and bathrooms, with a measurement accuracy of ±0.3℃/±2%RH. - Light Sensors
Working Principle: Light intensity is perceived through photoresistors or photodiodes, converting light signals into analog voltage signals, which are then output as digital signals after AD conversion.
Core Technical Parameters: Measurement range of 0-2000lux (indoor) or 0-10000lux (outdoor); accuracy ±5%; response time ≤1ms.
Representative Products: Huawei HiLink Light Sensor, supporting a wide range measurement of 0-10000lux, can automatically adjust the opening degree of smart curtains and the brightness of smart lights according to light intensity. When light intensity exceeds 800lux, it automatically turns off the main living room light and opens the sheer curtains; Philips Hue Light Sensor, adopting the Zigbee 3.0 protocol, has a linkage delay of <100ms with Hue smart lights, suitable for automatic light compensation in study reading areas. - Air Quality Sensors
Working Principle: Differentiated detection technologies are used for different pollutants—PM2.5 uses the laser scattering method, VOC uses semiconductor gas sensors, and carbon dioxide uses the infrared absorption method.
Core Technical Parameters: PM2.5 measurement range 0-500μg/m³ (accuracy ±10μg/m³); VOC measurement range 0-10mg/m³ (accuracy ±20%); carbon dioxide measurement range 0-5000ppm (accuracy ±50ppm).
Representative Products: Honeywell HPMA50E1, which can simultaneously detect PM2.5 and PM10 with a response time of <1s. After being integrated into the fresh air system, it can achieve "automatic ventilation when pollution exceeds standards"; Aqara Air Quality Sensor, supporting three-in-one detection of PM2.5, VOC, and carbon dioxide. When carbon dioxide concentration exceeds 1000ppm, it automatically opens windows or the fresh air system and pushes reminders to the user's mobile phone.
Human Perception Sensors: Achieving "Activate Upon Arrival, Deactivate Upon Departure"
These sensors are the key "switches" for triggering smart scenarios. By perceiving information such as human presence, movement, and gestures, they drive the automatic operation of devices like lights and home appliances, enhancing the convenience of home intelligence.
- Human Presence Sensors
Working Principle: Mainstream technologies include millimeter-wave radar and pyroelectric infrared (PIR). Millimeter-wave radar determines human presence by emitting high-frequency electromagnetic waves and receiving human reflection waves; PIR achieves perception by detecting changes in infrared rays emitted by the human body.
Core Technical Parameters: Millimeter-wave radar type has a detection distance of 0-10m (accuracy ±0.1m), can penetrate obstacles like wooden doors and glass, with a false alarm rate <0.1%; PIR type has a detection angle of 110°-170° and a detection distance of 0-7m, with a response time ≤0.5s.
Representative Products: Hi-Link HLK-LD2410 millimeter-wave human presence sensor, supporting continuous detection of stationary humans (such as an elderly person sitting on a sofa for a long time). When a human is detected, it keeps the living room lights on, and automatically turns them off 3 minutes after the person leaves; Aqara Human Presence Sensor FP2, adopting dual millimeter-wave + infrared detection technology, achieves a detection accuracy of ±0.05m and can distinguish between humans and pets (pets ≤20kg do not trigger it), suitable for households with pets. - Human Motion Sensors
Working Principle: Based on passive infrared (PIR) technology, when a human moves within the detection range, it causes changes in infrared radiation, and the sensor outputs a trigger signal.
Core Technical Parameters: Detection angle 120°-180°, detection distance 0-5m, response time ≤1s, false alarm rate <0.5% (can filter out pet and light/shadow interference).
Representative Products: Human Motion Sensor 2nd Generation, adopting lens optimization design with a detection angle of 170°, can link with entryway lights to achieve "lights on upon door opening," and automatically turns off 1 minute after the person leaves; Bosch ISW-ZPR1-WP13 infrared motion sensor, featuring an IP65 waterproof rating, can be installed on balconies to automatically close balcony windows when human motion is detected (paired with a smart window opener). - Gesture Recognition Sensors
Working Principle: Adopting visual recognition or radar technology—visual recognition captures gesture images through cameras and recognizes gesture commands via AI algorithms; radar technology recognizes gestures by detecting distance changes in gesture movements through millimeter-wave detection.
Core Technical Parameters: Visual type supports 5-10 types of gesture recognition (such as waving, clenching fists, thumbs up), with a recognition distance of 0.5-2m and an accuracy rate ≥95%; radar type supports 3-5 types of gesture recognition, with a recognition distance of 0.3-1.5m and a response time ≤0.3s.
Representative Products: Apple's built-in gesture recognition sensor, using U1 ultra-wideband radar, supports gestures such as waving to adjust volume and clenching fists to pause playback, with a recognition accuracy of 98%; Xiaomi Smart Speaker Play Enhanced Edition, achieving gesture recognition through a top-mounted camera, can control living room light brightness (waving up to brighten, down to dim), with a recognition distance of 1.5m.
Health Monitoring Sensors: Building a Home "Health Guardian Station"
These sensors focus on the real-time monitoring of physiological indicators and health status, especially suitable for the elderly and patients with chronic diseases, providing data support for home health management and achieving "early detection and early intervention."
- Heart Rate/Blood Oxygen Sensors
Working Principle: Adopting Photoplethysmography (PPG), it calculates heart rate by emitting red/infrared light and detecting blood volume changes, and calculates blood oxygen saturation through the absorption differences between red and infrared light.
Core Technical Parameters: Heart rate measurement range 30-200bpm (accuracy ±1bpm); blood oxygen measurement range 70%-100% (accuracy ±2%); sampling rate ≥100Hz.
Representative Products: The blood oxygen sensor built into the Apple Watch Series 9, using dual-beam PPG technology, can continuously monitor blood oxygen saturation, pushing alerts when blood oxygen drops below 90%, with data synchronizable to a family doctor APP; Xiaomi Smart Band 8's heart rate sensor supports 24-hour continuous monitoring and features heart rate abnormality (such as atrial fibrillation) recognition, with a false alarm rate <1%, suitable for daily heart rate monitoring of the elderly. - Blood Pressure Sensors
Working Principle: The mainstream method is the oscillometric method, which calculates systolic and diastolic pressure through algorithms by inflating an airbag and detecting pressure changes during arterial pulsation; some products adopt PPG+ECG (Electrocardiogram) fusion technology, requiring no airbag inflation.
Core Technical Parameters: Measurement range 60-200/40-130mmHg (accuracy ±3mmHg); PPG+ECG method measurement range 70-180/50-110mmHg (accuracy ±5mmHg); measurement time ≤1 minute.
Representative Products: Huawei WATCH D smartwatch, adopting the micro-airbag oscillometric method, has obtained Class II medical device certification by the National Medical Products Administration (NMPA). Its measurement accuracy is comparable to medical electronic blood pressure monitors, and it can automatically record blood pressure change trends and generate reports; Omron HBP-1100 wrist blood pressure sensor, using PPG+ECG technology, requires no inflation, completes measurement in 30 seconds, and data can be synchronized to a health cloud platform, supporting remote viewing by family members. - Fall Detection Sensors
Working Principle: Adopting fusion technology of a 3-axis accelerometer + gyroscope + barometer, it judges whether a fall has occurred by detecting human acceleration, angular velocity, and height changes; some products combine millimeter-wave radar to achieve non-contact fall detection.
Core Technical Parameters: Contact detection sensitivity ≥95%, false alarm rate <2%, response time ≤1s; non-contact detection distance 0-5m, detection angle 120°, capable of penetrating clothing for detection.
Representative Products: Philips Fall Detection Sensor DFM-300, worn on the waist, automatically sends alerts to emergency contacts' mobile phones and calls emergency services when a fall is detected, supporting voice confirmation (to avoid false alarms); Hikvision millimeter-wave fall detection sensor DS-2CD3T47WD-L, installed on the bedroom ceiling, can monitor the activities of the elderly 24 hours a day, with a fall detection accuracy of 96% and a false alarm rate <1.5%, suitable for households with elderly living alone.
III. Sensor Applications at the Physical Space Level
Entryway: Smart "Welcome Post", Initiating the First Step of Home Intelligence
As the entrance to the home, the entryway solves pain points such as "fumbling for switches in the dark" and "forgetting to close windows." The core role of sensors is to achieve "response upon arrival" while considering security functions. Main configurations include human motion, light, door/window, and temperature/humidity sensors. Typical linkage scenarios are as follows:
- Door Opening Linkage: When the door/window sensor detects the entrance door opening or someone in the entryway, the light sensor judges the current light intensity (if below 300lux), automatically turning on the entryway light and shoe cabinet light strip, while triggering a "door opened" reminder from the smart door lock to the user's mobile phone; if outdoor temperature and humidity are detected to be low (temperature <10℃ or humidity >80%RH), it automatically closes the balcony windows (paired with a smart window opener).
- Leaving Home Scenario: When no one is in the entryway (for 5 continuous minutes) and the door/window sensor detects the entrance door is closed, it automatically turns off the entryway light and shoe cabinet disinfection module (if available), and triggers the whole-house security system to arm (e.g., door/window sensors activate, cameras enter standby monitoring status).
- Implementation Cases: A certain project uses an Aqara human motion sensor + Aqara light sensor + door/window sensor to achieve fully automatic control of "lights on upon opening, lights off upon closing." According to resident feedback, the false trigger rate of entryway lighting is <1%, and by linking with a smart shoe cabinet, it solves the problem of shoes getting damp and moldy when entering in winter (the temperature and humidity sensor automatically activates the shoe cabinet's dehumidification function when humidity >70%RH).
Living Room: Smart "Interaction Center", Adapting to Multi-Scenario Needs
As the core area for family activities, the living room relies on sensors that balance multiple scenarios such as daily leisure, movie watching, and receiving guests, achieving automatic device switching and intelligent environmental adjustment, while ensuring the safety of the elderly and children. Core configurations include human presence, light, gesture recognition, temperature/humidity, and carbon dioxide sensors. Typical linkage scenarios are as follows:
- Movie Watching Mode: When a "clenched fist" gesture is detected (or triggered by voice command), the human presence sensor confirms someone is in the living room, automatically turning off the main light, turning on the movie-watching light strip (brightness adjusted to 10%), closing the smart curtains, and adjusting the air conditioner temperature to 24℃ and fan speed to low; if the carbon dioxide sensor detects concentration >1500ppm (when multiple people are watching), it automatically starts the fresh air system at low speed.
- Children's Activity Mode: When children are detected playing on the living room floor (identifying small-sized targets via millimeter-wave radar), it automatically locks the living room floor-to-ceiling windows (paired with smart window locks) and restricts the air conditioner fan speed to medium-low to avoid direct blowing and catching a cold; if the light sensor detects excessively strong sunlight (>10000lux), it automatically adjusts the curtain opening to 50% to prevent glare.
- Unoccupied Energy-Saving Mode: When no one is detected in the living room (for 10 continuous minutes), it automatically turns off all lights, TVs, air conditioners, and other devices. If temperature and humidity are suitable (22-26℃, humidity 40%-60%RH), it turns off the fresh air system to reduce energy consumption.
- Implementation Cases: A certain project uses Huawei human presence sensors + light sensors + gesture recognition sensors to create a "frictionless interaction" living room. When users walk into the living room, lights automatically adjust to a brightness suitable for the current light; users can switch TV channels and adjust volume by waving, without touching the remote control; the system automatically saves energy when unoccupied. According to calculations, monthly living room energy consumption is reduced by about 30% compared to traditional homes.
Bedroom: Smart "Rest Capsule", Focusing on Sleep Health and Comfort
The bedroom needs to ensure sleep quality and morning convenience, requiring "non-intrusive monitoring" and "precise response." Especially for the elderly, nighttime safety monitoring and emergency response functions need to be strengthened. Core configurations include millimeter-wave human presence, sleep monitoring (bed-use), light, temperature/humidity, and fall detection sensors. Typical linkage scenarios are as follows:
- Pre-Sleep Mode: When a user is detected entering the bedroom (for 5 continuous minutes) and the light is detected to be dimming (<100lux), it automatically turns off the main bedroom light and turns on the bedside reading light (brightness adjusted to 30%); after the sleep monitoring sensor (bed-use) detects the user lying in bed, it automatically turns off the reading light, adjusts the air conditioner to sleep mode (23℃, silent operation), and closes the smart curtains.
- Nighttime Waking: When a user is detected getting out of bed (between 22:00 and 06:00 the next day), it automatically turns on the under-bed light strip and corridor night light (brightness ≤50lux to avoid strong light stimulation) and turns on the bathroom light; if the fall detection sensor (installed in the bedroom corner) detects an abnormal posture (such as a fall), it immediately pushes an alert to the emergency contact's mobile phone and turns on the bedroom sound and light alarm.
- Morning Wake-up Mode: Detecting the end of the user's sleep cycle (such as the light sleep stage), 30 minutes before the set wake-up time, it gradually brightens the bedroom curtains (simulating natural light) while slowly increasing the bedside lamp brightness; when the temperature and humidity sensor detects bedroom humidity <40%RH, it automatically turns on the humidifier until humidity reaches 50%RH.
- Implementation Cases: Bedrooms in a certain elderly care community use millimeter-wave human presence sensors + sleep monitoring sensors + fall detection sensors to provide nighttime safety guarantees for elderly living alone. According to community statistics, after installation, the false alarm rate for nighttime falls among the elderly is <2%, truly achieving "immediate response to abnormalities, no disturbance when normal"; meanwhile, sleep monitoring data is synchronized to the community health management platform, allowing doctors to adjust the elderly's routine recommendations based on the data to improve sleep quality.
Kitchen: Smart "Safety Guardian", Balancing Cooking Convenience and Hazard Prevention
The kitchen is the "critical area for fire and electricity" in the home. The core role of sensors is to ensure safety (such as gas leak and fire warnings) while improving cooking efficiency and solving pain points like "forgetting to turn off the stove" and "food spoilage." Core configurations include gas, smoke, temperature/humidity, human motion, and refrigerator temperature/humidity sensors. Typical linkage scenarios are as follows:
- Gas Safety Warning: When gas concentration is detected to exceed 0.1% of the Lower Explosive Limit (LEL), it immediately triggers a sound and light alarm, automatically closes the gas valve (paired with a smart gas valve), and pushes alerts to the user's mobile phone and the property platform; if the human motion sensor detects no one in the kitchen, it turns on the kitchen exhaust fan at high speed to accelerate gas dispersion.
- Cooking Assistance Scenario: When a user is detected entering the kitchen, it automatically turns on kitchen lighting (adjusting brightness based on light sensor data); when the temperature and humidity sensor detects kitchen humidity >70%RH (such as when washing vegetables), it automatically activates the dehumidification module under the wall cabinet; if the smoke sensor detects a small amount of cooking fumes (not reaching the alarm threshold), it automatically adjusts the range hood fan speed to medium.
- Food Freshness Reminder: The refrigerator temperature and humidity sensor monitors the internal temperature (normal range 2-8℃) and humidity (40%-60%RH) in real time. When the temperature exceeds 8℃ for 1 hour, it pushes a "refrigerator temperature abnormal, check cooling" reminder; if humidity in a specific area (such as the fruit and vegetable box) is detected >90%RH, it pushes a "food prone to mold, recommend lowering humidity" prompt.
- Implementation Cases: A certain project uses gas sensors + smoke sensors + refrigerator temperature/humidity sensors to achieve full-scenario intelligent prevention and control in the kitchen. According to property statistics, the false alarm rate for gas leaks in this project's kitchen is <0.5%, and through refrigerator sensor reminders, users' food waste rate has decreased by about 20% compared to before; in the cooking scenario, the automatic adjustment function of the range hood eliminates the need for manual operation, enhancing the cooking experience.
Bathroom: Smart "Comfort Space", Focusing on Health and Convenience
Bathroom applications need to balance privacy protection (using non-contact sensors), health monitoring (such as water quality and air), and convenient experiences (such as automatic flushing and warm air drying), while optimizing safety functions for the elderly. Core configurations include millimeter-wave human presence, water quality, temperature/humidity, odor, and fall detection sensors. Typical linkage scenarios are:
- Toilet Scenario: When a user is detected entering the toilet area, it automatically turns on the toilet seat heating (adjusting temperature based on temperature and humidity sensor data, set to 37℃ in winter and turned off in summer) and turns on the exhaust fan at low speed; after the user gets up and leaves, it automatically triggers the toilet flush (distinguishing between large/small flushes based on stay duration) and increases the exhaust fan speed to high, returning to low speed after 3 minutes.
- Bathing Scenario: When a user is detected entering the shower area and the temperature and humidity sensor detects the current temperature <25℃, it automatically turns on the bathroom heater's warm air function, adjusting the temperature to 30℃; when the water quality sensor detects water temperature >45℃, it pushes a "water temperature too high, please note" reminder; after bathing, it continuously monitors bathroom humidity, keeping the bathroom heater's ventilation function on when humidity >80%RH until humidity drops to 60%RH.
- Elderly Safety Protection: Millimeter-wave human presence sensors can be installed in bathroom corners to monitor the activity status of the elderly in real time. When a fall is detected, it immediately pushes an alert to emergency contacts and simultaneously shuts off the bathroom hot water supply (to avoid secondary injuries); when the odor sensor detects that bathroom odor concentration exceeds standards (such as ammonia concentration >10ppm), it automatically turns on the exhaust fan and pushes a "bathroom needs cleaning" reminder.
- Implementation Cases: A certain apartment's bathroom uses millimeter-wave human presence sensors + water quality sensors + fall detection sensors, significantly improving the safety of the elderly during toilet use and bathing. According to apartment nursing staff feedback, the fall alarm response time for the elderly in the bathroom has been reduced from the previous 5 minutes to within 1 minute, and the water quality sensor effectively avoids scalding issues caused by excessively high water temperatures; the odor monitoring function also keeps the bathroom environment clean, reducing the risk of bacterial growth.
Balcony: Smart "Multi-Functional Area", Adapting to Laundry, Drying, and Leisure Needs
Balcony applications need to combine multi-functional needs such as laundry and drying, plant care, and leisure sightseeing, achieving automatic device operation and intelligent environmental adjustment, with special attention to the "weather adaptation" of clothes drying. Core configurations include light, temperature/humidity, wind/rain, human motion, and soil humidity sensors. Typical linkage scenarios are:
- Laundry and Drying Linkage: When the washing machine completes washing (via smart washing machine linkage signal), the human motion sensor detects no one on the balcony, the light sensor judges the current light intensity >5000lux (suitable for drying), and the wind/rain sensor detects no rain or strong wind (wind speed below a preset threshold, e.g., below 10 m/s), the smart clothes rack automatically lowers to receive the laundry and then rises to the drying position.
- Plant Care Scenario: Soil humidity sensors monitor the soil humidity of balcony potted plants (different plants have different thresholds, such as pothos suitable humidity 60%-80%RH). When humidity drops below the threshold, it automatically turns on the smart flower watering device until suitable humidity is reached; when the light sensor detects excessively strong sunlight (>80000lux), it automatically adjusts the shading curtain opening to 30% to avoid plant sunburn; when the temperature and humidity sensor detects temperature >35℃, it turns on the balcony mist cooling device.
- Leisure Scenario: When a user is detected entering the balcony leisure area (such as near the tea table), the light sensor judges the current light is soft (1000-5000lux), automatically turning on the balcony ambient light (warm light mode) and adjusting the shading curtain to a half-open state; if the temperature and humidity sensor detects suitable outdoor temperature (20-26℃), it automatically opens the balcony sliding door to maintain air circulation.
- Implementation Cases: A certain apartment's balcony uses light sensors + wind/rain sensors + soil humidity sensors to create an integrated "smart drying + plant care" scenario. User feedback indicates that the linkage between the washing machine and clothes rack saves manual operation time; the application of wind/rain sensors avoids the embarrassment of "forgetting to bring in clothes on rainy days" multiple times; plant care sensors have increased the survival rate of potted plants by about 40%, especially suitable for users with busy work schedules who have no time to tend to plants.
IV. Sensor Technologies and Applications for Target Service Groups
The essence of smart homes is to provide personalized, safe, and convenient living experiences for different groups. Addressing the differentiated needs of the elderly, infants and toddlers, adults, and special groups, through precise sensor configuration and smart terminal linkage, "on-demand services" can be realized, allowing the home environment to truly adapt to the living habits and health status of every family member.
The Elderly: Focusing on Health Guardian, Safety, and Convenience, Building an Age-Friendly Smart Environment
Due to declining physiological functions, the elderly have extremely high demands for "health monitoring accuracy," "timeliness of safety protection," and "operational convenience" in their home environments. Sensors need to deeply coordinate with wearable devices and medical terminals to form a full-cycle protection system.
- Core Needs and Sensor Configuration
(1) Health monitoring needs: Match with wearable heart rate and blood pressure sensors, bed-use sleep monitoring sensors, and sweat glucose sensors (for non-invasive blood glucose trend monitoring) to capture physiological indicator fluctuations in real time;
(2) Safety protection needs: Configure millimeter-wave fall detection sensors (installed in bedrooms and bathrooms), gas and door/window sensors (to monitor abnormal entry/exit), and water immersion sensors (to prevent slipping from leaks);
(3) Living convenience needs: Equip with smart pillbox sensors (such as pillboxes with medication reminders, pushing alerts if medication is not taken on time), human presence sensors (to achieve automatic lighting when getting up at night), and voice control sensors (such as voice modules for hands-free appliance operation). - Typical Linkage Scenarios
(1) Health monitoring closed-loop: Wearable heart rate and blood pressure sensors automatically measure data every hour. If systolic pressure >160mmHg or heart rate <50bpm, it immediately pushes alerts to children's mobile phones and the community medical center; if the sleep monitoring sensor detects nighttime sleep apnea exceeding 10 seconds, it links with the bedside fresh air system to increase fan speed, while recording data to generate a weekly health report synchronized to the family doctor APP.
(2) Fall emergency response: After the millimeter-wave fall detection sensor detects an elderly person falling, it triggers a sound and light alarm within 1 second, automatically calls emergency contacts, and sends location; if no human response is received within 5 minutes, it links with the community elderly care service platform to send staff for an on-site check, while closing the bathroom hot water valve (to avoid secondary injuries).
(3) Smart medication management: Prescribe medication times (e.g., 7:00 AM, 7:00 PM). When the time arrives, a voice reminder "Time to take medicine" is issued. If the pillbox is not opened within 15 minutes, an alert is pushed to children's mobile phones; when the remaining medication in the pillbox is less than a 3-day supply, it automatically reminds children or links to an online pharmacy to place a replenishment order.
(4) Terminal coordination solution: Centered on "smart bracelet + home control screen + community medical platform," the smart bracelet collects physiological data in real time, the home control screen displays health trends and device status, and the community medical platform receives abnormal alerts and provides remote guidance, forming an "individual-family-community" three-level protection network.
Infants and Toddlers: Focusing on Environmental Safety and Health Guardian, Creating a Worry-Free Growth Space
Infants and toddlers have immature immune systems and lack self-protection capabilities. Sensors need to focus on "environmental cleanliness," "abnormal status warnings," and "accident prevention," combining baby monitors and smart maternal/infant home appliances to build a safe and comfortable growth environment.
- Core Needs and Sensor Configuration
(1) Environmental safety needs: Match with high-precision temperature and humidity sensors (temperature control accuracy ±0.3℃), formaldehyde/TVOC sensors, and CO₂ sensors to monitor air quality in bedrooms and baby rooms in real time;
(2) Health guardian needs: Configure cry recognition sensors, non-contact body temperature sensors, and diaper humidity sensors (such as smart diaper reminders) to promptly capture abnormal baby status;
(3) Accident prevention needs: Equip with millimeter-wave human presence sensors (to monitor bed falls), door/window sensors (to prevent babies from accidentally opening windows), and dangerous area infrared sensors (installed at kitchen and balcony doors). - Typical Linkage Scenarios
(1) Intelligent environmental adjustment: When the temperature and humidity sensor detects baby room temperature >28℃ or humidity >70%RH, it automatically turns on the baby air conditioner (set to 26℃) and dehumidifier, while turning off the fresh air system's return air mode (to avoid external pollution); if the formaldehyde sensor detects concentration >0.08mg/m³, it immediately starts the air purifier at high speed, pushes an alert to parents' mobile phones, and reminds "not suitable for the baby to stay in the room."
(2) Abnormal status response: The cry recognition sensor distinguishes between "hunger cry," "discomfort cry," and "startled cry." If judged as a hunger cry (short and rapid), it links with the smart bottle warmer to start heating breast milk; if it is a discomfort cry (accompanied by body temperature sensor detecting temperature >37.5℃), it pushes a "baby may have a fever, needs checking" reminder and turns on the soft bedside night light; after the diaper humidity sensor detects moisture, it triggers the baby bed vibration soother and pushes a "diaper needs changing" prompt.
(3) Accident prevention protection: Millimeter-wave human presence sensors are installed around the baby crib. When a baby's body part is detected extending beyond the bed edge (a precursor to falling), it immediately emits a high-frequency alarm sound to remind parents. If parents do not respond and the baby continues to move, it links with the baby crib guardrail to automatically rise (requires pre-configuration of a smart guardrail); dangerous area infrared sensors detect the baby approaching the kitchen, automatically closing the kitchen door (paired with a smart door catch) and displaying "baby entered dangerous area" on the control screen.
(4) Terminal coordination solution: Centered on "baby monitor + smart maternal/infant home appliances + parents' mobile APP," the baby monitor integrates temperature, humidity, cry, and body temperature data. Smart maternal/infant home appliances (such as air conditioners, purifiers, bottle warmers) operate automatically based on sensor signals, and the parents' mobile APP receives alerts and environmental data in real time, supporting remote viewing of the baby's status.
Adults: Balancing Security, Comfort, and Efficiency, Building a Convenient Smart Life
As the main force of the family, adults place more emphasis on "security reliability," "environmental comfort," and "life efficiency improvement" in their smart home needs. Sensors need to link with smart home appliances and office equipment to reduce repetitive operations while ensuring home safety.
- Core Needs and Sensor Configuration
(1) Home security needs: Match with smart door locks (such as Dessmann Q50MPro, with fingerprint/facial recognition + abnormal unlocking alerts), door/window sensors (such as Xiaomi Door/Window Sensor 2, monitoring window prying and unclosed windows), smart cameras (such as EZVIZ C6CN, with motion detection + human shape recognition), and smoke sensors (such as Jade Bird JTY-GD-JBF-3110);
(2) Environmental comfort needs: Configure temperature and humidity sensors (such as Aqara Temperature and Humidity Sensor), light sensors (such as Philips Hue Light Sensor), and PM2.5 sensors (such as Honeywell HPMA115S0) to automatically adjust the home environment;
(3) Efficiency improvement needs: Equip with human presence sensors (such as Aqara FP2), sedentary reminder sensors (such as Huawei Smart Cushion), and home appliance status sensors (such as Xiaomi Smart Socket, monitoring appliance power consumption and switch status). - Typical Linkage Scenarios
(1) Smart security closed-loop: When the smart door lock detects an unknown fingerprint attempting to unlock, it immediately pushes an alert to the mobile phone and links with the doorway camera to record a 10-second video sent to the user; when the door/window sensor detects a window being pried, it triggers the whole-house sound and light alarm and pushes an alert to the property security center; when the smoke sensor detects smoke, it automatically closes the gas valve, opens windows (paired with a smart window opener), and calls the fire alarm number (requires prior authorization).
(2) Adaptive environmental adjustment: When the light sensor detects excessively strong daylight in the living room, it automatically adjusts the smart curtain opening to 30% and links with living room lights to adjust to warm light mode (brightness 30%); when the temperature and humidity sensor detects indoor humidity <30%RH in winter, it automatically turns on the humidifier, stopping when humidity reaches 50%RH; when the PM2.5 sensor detects outdoor smog (PM2.5 >150μg/m³), it automatically closes all exterior windows and turns on the fresh air system's internal circulation mode.
(3) Efficiency and health management: When the human presence sensor detects a user sitting at the desk, it automatically turns on the desk lamp and links with the computer to start office mode; when the sedentary reminder sensor detects continuous sitting for over 1 hour, it pushes a "please get up and move" reminder and links with the smart bracelet for vibration prompts. If the user does not respond, the desk lamp will flash 3 times to strengthen the reminder; when the home appliance status sensor detects the TV has been on standby for over 30 minutes, it automatically cuts off power to avoid standby power consumption.
(4) Terminal coordination solution: Centered on "smart speaker + mobile APP + smart control screen," users can control remotely via voice (smart speaker) or mobile APP, or manage all devices visually through the control screen. For example, after an employee's family at a certain tech company in Shenzhen adopted this solution, monthly home energy consumption decreased by 25%, safety hazards caused by forgetting to turn off appliances or close windows decreased by 90%, and daily household operation time saved about 1 hour/day.
Special Groups: Focusing on Accessibility and Customization, Providing Precise Smart Assistance
Special groups refer to those with special needs due to physiological functions or health conditions, including people with physical disabilities, visually impaired individuals, and patients with chronic diseases. Their needs differ significantly from the general population, requiring customized smart solutions. They have needs for "accessible interaction," "customized health management," and "emergency assistance." Sensors need to combine with auxiliary equipment to achieve "compensating for functional defects" and "reducing life dependence."
- Core Needs and Sensor Configuration
(1) Accessible interaction needs: Match with voice control sensors (supporting dialect recognition), gesture recognition sensors (supporting simple gestures like waving and clenching fists), and eye-tracking sensors (suitable for severely disabled individuals);
(2) Customized health management needs: Configure medical-grade blood glucose sensors, blood pressure sensors, and lung function sensors (such as smart spirometers, suitable for asthma patients), supporting automatic data upload to medical platforms;
(3) Emergency assistance and life assistance needs: Equip with one-key alarm sensors (such as pull-cord emergency buttons installed by the bed or wheelchair), item positioning sensors, and smart navigation sensors (such as guide bracelets for the visually impaired with ultrasonic obstacle avoidance). - Typical Linkage Scenarios
(1) Accessible home control: Visually impaired individuals say "turn on the living room light" through voice control sensors, and the system automatically recognizes and turns on the light, while providing voice feedback "living room light is on, brightness 100%"; physically disabled individuals wave left with gesture recognition sensors to change TV channels and wave right to adjust volume; severely disabled individuals gaze at the "air conditioner" icon for 3 seconds through eye-tracking sensors to automatically turn on the air conditioner, and gaze at the temperature number "26" to adjust the temperature.
(2) Chronic disease management closed-loop: Blood glucose sensors automatically measure blood glucose every 15 minutes. If blood glucose >11.1mmol/L (postprandial) or <3.9mmol/L (fasting) is detected, it immediately pushes alerts to the patient's mobile phone, family members' mobile phones, and the attending physician, linking with the smart pillbox to dispense hypoglycemic agents/candy reminders (distinguishing between hyperglycemia/hypoglycemia), while pushing dietary advice (such as "need to reduce staple food intake"); when the lung function sensor detects an asthma patient's breathing rate >30 times/minute, it automatically turns on the air purifier (to filter allergens), links with the fresh air system to increase fan speed, and pushes a "may induce asthma, recommend staying away from allergens" reminder.
(3) Emergency assistance and life assistance: When the one-key alarm sensor is triggered, the system immediately calls emergency contacts, sends a help message with location, and links with the community service center; when the item positioning sensor detects the user looking for keys (triggered via mobile APP), the sensor on the keys emits a beep, and the mobile APP displays the key location (accuracy ±1m); the ultrasonic sensor on the visually impaired guide bracelet detects an obstacle 1 meter ahead, immediately vibrating to remind, while broadcasting "tables and chairs ahead, please detour to the left."
(4) Terminal coordination solution: Centered on "auxiliary equipment (such as guide bracelets, smart wheelchairs) + medical platform + community service center," auxiliary equipment collects user status and environmental data, the medical platform provides professional health guidance, and the community service center receives emergency assistance and responds quickly.
V. Development Trends and Challenges of Sensors in Smart Homes
Given the continuous progress of IoT and AI technologies, sensors, as the "perception cornerstone" of smart homes, are continuously expanding their application scenarios, and their technical performance is also rapidly upgrading. However, sensors still face many challenges in terms of compatibility, security, and cost, all of which will affect the popularization speed and user experience of smart homes.
Technology Development Trends
- Technological Integration: Deep Combination of Multi-Sensor Integration and AI Algorithms
Future smart home sensors will no longer be single-function "information collectors" but will develop towards multi-parameter integration. For example, a sensor installed in a bedroom can simultaneously monitor multiple data points such as temperature, humidity, light, PM2.5, human presence status, and sleep quality. Through AI algorithms, these data are fused and analyzed to achieve more precise scenario judgments. For instance, when the sensor detects that the user turns over frequently during sleep (combined with sleep monitoring data) and indoor humidity >70%RH, it will automatically judge it as "sleep environment discomfort caused by dampness" and then link with the dehumidifier and air conditioner to adjust the environment without manual operation by the user. Additionally, AI algorithms can optimize sensor trigger thresholds by continuously learning user habits, such as adjusting night light brightness in advance based on the user's nighttime waking routine to reduce sleep interference. - Miniaturization and Low Power Consumption: Enhancing Concealment and Battery Life
To better integrate sensors into the home environment without destroying decoration aesthetics, miniaturization will become a critical development direction. Future sensors may be made as small as buttons or stickers, hidden in walls, furniture crevices, or even inside home appliances. For example, micro door/window sensors can be directly attached to drawer edges to monitor whether children open dangerous drawers; micro temperature and humidity sensors can be embedded inside wallpaper to monitor the indoor environment in real time. Meanwhile, advancements in low-power technology will significantly extend sensor battery life. Sensors using energy harvesting technology (such as using light, heat, or vibration energy for power) will gradually become popular, eliminating the trouble of battery replacement. For example, a light sensor installed on a window can work by absorbing electrical energy converted from sunlight, achieving "lifetime maintenance-free." - Scenario-Based Customization: Developing Dedicated Sensors for Segmented Needs
As users' demands for smart homes become increasingly personalized, dedicated sensors for specific scenarios and specific groups will continue to emerge. For example, for pet families, "pet activity monitoring sensors" will appear, which can identify pet behaviors (such as scratching furniture, rummaging through trash cans), link with cameras to push reminders, and also monitor pets' body temperature and water intake to promptly discover health issues; for fitness enthusiasts, "home fitness sensors" will appear, which can be installed on yoga mats and dumbbells to monitor exercise posture and exertion intensity in real time, providing correction suggestions through AI analysis and linking with smart TVs to display sports data, creating a "home gym" scenario. Additionally, "food freshness sensors" for kitchen scenarios and "clothing humidity sensors" for wardrobes will also become important tools for improving home experiences. - Security and Privacy Protection: Building a Solid Data Defense Line from a Technical Perspective
As sensors collect more and more data (including users' physiological data, activity trajectories, living habits, etc.), data security and privacy protection will become the core focus of sensor development. Future sensors will adopt hardware encryption, edge computing, and other technologies to ensure data is not leaked during collection, transmission, and storage. For example, wearable health sensors will encrypt data such as heart rate and blood pressure locally, uploading only the encrypted abnormal data to the cloud to avoid exposing raw data; edge computing technology allows sensors to complete data processing and scenario judgments locally, reducing the amount of data transmitted to the cloud and lowering the risk of data interception. Meanwhile, smart home systems will provide more transparent privacy settings, allowing users to independently choose the collection scope and storage duration of sensor data, and even delete historical data with one click, giving users absolute control over their personal information.
Challenges Faced by the Industry
- Compatibility Issues: Difficulty in Interconnection Among Sensors of Different Brands
Currently, there are numerous smart home sensor brands on the market, such as Xiaomi, Huawei, Aqara, and EZVIZ. Each brand has its own communication protocols (such as Zigbee, Wi-Fi, Bluetooth Mesh) and ecosystems, making it difficult for sensors of different brands to be compatible. For example, Xiaomi's human sensor cannot directly link with Huawei's smart lights. If users want to build a cross-brand smart home system, they need to purchase additional third-party control devices for protocol conversion, which not only increases costs but may also cause response delays and command loss. This "ecological barrier" seriously hinders the scaled development of smart homes. How to formulate unified industry standards to achieve seamless interconnection among sensors of different brands is an urgent problem to be solved. - Cost and Cost-Effectiveness: High Prices of High-End Sensors Make Popularization Difficult
Although the prices of basic sensors (such as temperature/humidity, door/window) have dropped to tens of yuan, the prices of high-end sensors with high precision, multi-parameters, and AI functions remain high. For example, a bed-use sensor that can simultaneously monitor sleep quality, heart rate, and breathing rate usually costs over a thousand yuan; multi-functional sensors supporting AI voice recognition and gesture control generally cost over 500 yuan. For ordinary families, purchasing a large number of high-end sensors will increase the construction cost of smart homes, causing many users to only choose basic sensors and unable to experience smarter scenario services. How to reduce the manufacturing cost of high-end sensors while ensuring performance and improve cost-effectiveness is a difficult problem for sensor manufacturers to overcome. - Insufficient Environmental Adaptability: Some Sensors Are Susceptible to External Interference
Currently, the working performance of many sensors is greatly affected by the environment, leading to inaccurate data and false triggers. For example, millimeter-wave fall detection sensors may experience missed detections or misjudgments in complex home environments (such as furniture obstruction, multiple people moving simultaneously); optical smoke sensors are prone to false fire alarms in kitchen environments with heavy cooking fumes; temperature and humidity sensors will experience decreased accuracy after long-term use in high-temperature and high-humidity environments such as bathrooms. Additionally, sensors have high requirements for installation positions. Improper installation (such as too close to an air conditioner outlet or blocked by curtains) will further affect data accuracy. How to improve the anti-interference ability of sensors and enhance their adaptability to different home environments is critical to improving user experience. - Low Level of Intelligence: Insufficient Functional Awareness and Low Usage Efficiency
On the one hand, complex product manuals and unfriendly interactive interfaces make it difficult for users to operate. The setup process for sensors is often complex, requiring users to download APPs, connect to networks, and set linkage scenarios. For the elderly or users unfamiliar with smart devices, the operation threshold is high. On the other hand, users have insufficient awareness of sensor functions and find it difficult to fully utilize them. For example, some users buy human presence sensors but only use them to control light switches, not knowing they can also link with air conditioners and fresh air systems; some users are unaware of the impact of sensor installation positions on performance, placing them randomly and causing frequent false triggers. How to help users quickly understand sensor functions and usage methods through easy-to-understand manuals, video tutorials, and more friendly interactive interfaces to improve usage efficiency is a critical link in promoting sensor popularization.
Future Outlook
Despite facing many challenges, the application prospects of sensors in smart homes remain broad. Given continuous technological breakthroughs, future sensors will be more intelligent, convenient, and secure, becoming a critical bridge connecting the physical and digital worlds. On the one hand, sensors will deeply integrate into people's daily lives, shifting from "passive response" to "active service," such as analyzing users' health data to provide early warnings of potential diseases and automatically optimizing the home environment by learning users' living habits. On the other hand, sensors will drive smart homes from "single-product intelligence" to "whole-home intelligence," achieving seamless coordination among different devices and scenarios, making the home environment truly a caring partner that "understands users." Meanwhile, given the gradual unification of industry standards and continuous cost reduction, sensors will enter more ordinary families, making smart homes no longer limited to high-end consumption but becoming an important choice for more and more families to improve their quality of life.
Conclusion
The market size of sensors in smart homes continues to expand. According to relevant data, the global smart home sensor market size is expected to exceed 60 billion US dollars by 2025 and is projected to surpass 100 billion US dollars by 2030. Meanwhile, market competition is also driving the improvement of product cost-effectiveness. High-end sensors are gradually entering ordinary families, and the industry ecosystem is shifting from "single-product competition" to "ecological coordination." More and more brands are beginning to open protocols to promote cross-brand interconnection.
In the future, given the unification of industry standards, further cost reduction, and the deep integration of sensors with technologies such as 5G, edge computing, and blockchain, sensors will not only achieve seamless coordination of home devices but also connect homes with external scenarios such as communities, healthcare, and services, forming a new ecosystem of "Whole-Home Intelligence + Full-Domain Services."
Ultimately, the core of smart homes is "people," and sensors are precisely the link connecting people with the home environment and external services. It is believed that in the near future, given the continuous evolution of technology and the market, smart homes will truly achieve a good experience "personalized for every individual," allowing every family to enjoy the beautiful life brought by technology.
(The next issue of this column will launch the third article on "Consumer Electronics Sensors," stay tuned!)
Author | Guo Yuansheng, Deputy Director of the Science and Technology Committee of the Jiusan Society Central Committee, Executive Vice Chairman of the China Sensor and IoT Industry Alliance Editor | Yang Pengyue, Art Editor | Ma Liya, Supervisor | Zhao Chen