Editor's Note: Sensors, as the "nerve endings of the information age," 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 Central Committee of the Jiusan Society and Executive Vice Chairman of the China Sensor and IoT (Internet of Things) Industry Alliance, to open a column titled "Guo Yuansheng Explains Sensors." The column focuses on eight major fields and scenarios: electric power, major equipment, intelligent manufacturing, smart agriculture, smart healthcare and big health, smart home appliances and consumer electronics, urban security, and low-altitude economy. Articles such as "Sensors 'Stationed' on the Power Generation Side: The Cornerstone of Stable Operation in New Power Systems" and "Sensors for Energy Storage: Clarifying Three Core Development Directions" have been published sequentially, receiving widespread attention and high praise from readers. This publication is the first in the consumer electronics field, focusing on smart home appliance sensors, elaborating on their application prospects, industrial status, and future suggestions to form industrial consensus and promote industrial development.
From the "three major items" represented by color TVs, refrigerators, and washing machines in the 1990s to the current consumer mainstream of smart air conditioners, IoT refrigerators, and washer-dryer combos, the development of the home appliance industry has always resonated with technological innovation and is closely linked to the upgrading of consumer demands. Given the popularization of technologies such as IoT and AI (Artificial Intelligence), consumer demands for home appliances have shifted from "usable and easy to use" to smart and personalized. Consumers not only require home appliances to have more precise functional implementation capabilities but also expect them to proactively adapt to life scenarios, anticipate user needs, and even achieve autonomous decision-making and operation.
In this wave of intelligent upgrading, sensors play an irreplaceable key and core role. For example, when an infrared sensor detects someone in the bedroom and the ambient temperature is above 26°C, it transmits the data to the main control chip of the smart air conditioner. The chip combines the data from the humidity sensor to determine whether to activate the cooling mode, then commands the compressor to start and adjusts the wind speed; when the washing machine sensor detects that the dirt concentration in the washing water has dropped below the threshold, it feeds back a signal to prompt the machine to automatically shorten the washing time, ensuring cleaning effectiveness while saving water and electricity. It can be said that without the precise perception of sensors, the "intelligence" of home appliances would be out of the question, and their essence would remain no different from traditional home appliances.
I. Application of Smart Sensors in the Home Appliance Field
The application of smart sensors in different home appliance categories all takes "solving functional detail problems" as the core goal. Combined with the functional attributes and usage scenarios of home appliances, differentiated technical solutions have been formed, allowing people to obtain an in-depth smart experience. From controlling basic environmental parameters such as temperature and humidity to complex needs like identifying ingredients and monitoring water quality, the depth and breadth of sensor applications are steadily expanding, driving home appliance products towards more precise, smarter, and more humanized directions.
(I) Large Home Appliances: Sensing Technology Applications in Core Scenarios
As core equipment for daily life, large home appliances feature high usage frequency, high functional complexity, and close integration with life scenarios. Their intelligent upgrading poses higher requirements for the precision, stability, and integration of sensors. The four major categories—air conditioners, refrigerators, washing machines, and color TVs—correspond to the four core scenarios of "environmental regulation," "ingredient storage," "garment care," and "entertainment interaction," respectively. Sensor applications have also formed mature technical systems around these scenarios.
1. Air Conditioners: Creating a Proactive Comfort Environment for Personalized Needs
Smart air conditioners rely on the collaboration of multiple types of sensors to comprehensively monitor the indoor and outdoor environment, human status, and the air conditioner's own operating status, achieving a transition from "passive adjustment" to "proactive service."
Core Sensor Types and Application Functions Temperature sensors are the most configured sensors in air conditioners. Their main function is to collect temperature data in real time, providing a basis for switching between cooling and heating modes and temperature adjustment, with an accuracy of up to ±0.5°C. They are responsible for detecting indoor, outdoor, and evaporator temperatures, respectively: the indoor one is installed at the air return outlet of the air conditioner to ensure the output temperature matches the set temperature; the outdoor one monitors the outdoor ambient temperature, and when the outdoor temperature is too low or too high, the air conditioner adjusts the operating frequency of the compressor based on its data to avoid damage to the compressor due to extreme temperatures; the evaporator temperature sensor monitors and prevents frosting or overheating of the evaporator, ensuring the operating efficiency and service life of the air conditioner.
Humidity sensors are key components for enhancing air conditioner comfort. They are used to monitor indoor air humidity in real time (the measurement range is usually 20%-90% RH). When the humidity is below or above the comfort threshold (generally 40%-60% RH), the dehumidification or humidification function will be automatically activated (for some air conditioners with humidification modules).
Air quality sensors upgrade air conditioners from "temperature regulators" to "air purifiers," mainly including PM2.5 sensors and VOC sensors. When the concentration of fine particulate matter in the indoor air exceeds the set value, the air conditioner will automatically activate the fresh air or purification function, filtering particulate matter through a filter; the VOC sensor is used to detect the content of volatile organic compounds such as formaldehyde and benzene indoors, with a response time usually no more than 10s, enabling quick capture of changes in indoor air quality. Some high-end air conditioners are also equipped with CO₂ sensors. When high indoor CO₂ concentrations are detected (e.g., when there are many people), the fresh air volume is automatically increased to improve the oxygen content in the indoor air.
Human body infrared sensors are the core for realizing "humanized services." By detecting the infrared rays emitted by the human body, they determine whether there is someone indoors and the activity area of the personnel. When the sensor detects no one indoors, the air conditioner will automatically enter energy-saving mode or shut down to avoid energy waste; when it detects personnel moving in a specific area (e.g., the living room sofa), it adjusts the air outlet direction of the air conditioner to that area to achieve "directional air supply"; it can even combine AI algorithms to judge the user's sleep status, automatically adjusting the temperature and wind speed at night, appropriately raising the temperature and reducing the wind speed during the deep sleep stage to prevent the user from catching a cold.
Vibration sensors are installed on the compressor shell, mainly monitoring the compressor's operating status to ensure the stable operation of the air conditioner and prevent the expansion of faults. They can also optimize the operating parameters of the compressor to improve operating efficiency.
Some high-end air conditioners also introduce millimeter-wave radar, which can not only determine whether there is someone indoors but also recognize the user's posture (e.g., standing, sitting, lying down), thereby more precisely adjusting the air outlet direction and wind speed.
Sensor Configuration and Application Scenario Implementation In terms of configuration quantity, the sensor configurations of different types of air conditioners vary greatly: conventional wall-mounted air conditioners, due to relatively concentrated functions, are usually configured with 5-7 sensors, including 1 indoor temperature sensor, 1 outdoor temperature sensor, 1 evaporator temperature sensor, 1 humidity sensor, 1 air quality sensor, 1 human body infrared sensor, and 1 vibration sensor; while central air conditioners, which need to adjust the environment of multiple rooms simultaneously, have a larger number of sensor configurations, usually configuring 3-5 sensors per indoor unit (including temperature, humidity, human body infrared sensors, etc.), and the outdoor unit is separately configured with temperature, vibration, and other sensors, with the overall configuration quantity reaching 10-20 or even more.
2. Refrigerators: The Leap from "Low-Temperature Storage" to "Smart Management"
Smart refrigerators achieve comprehensive monitoring and management of the storage environment and ingredient status by configuring multiple types of sensors, solving the pain points of traditional refrigerators such as "forgotten ingredients spoiling," "different ingredients mixing odors," and "uneven temperature control," becoming the core hub for "precise storage + smart management" of household ingredients.
Core Sensor Types and Application Functions The application of temperature sensors in refrigerators features "zoning and precision." Unlike traditional refrigerators that only configure 1-2 temperature sensors, smart refrigerators are equipped with independent temperature sensors in different compartments such as the refrigerating compartment, freezing compartment, and variable temperature compartment. Some high-end refrigerators also configure additional sensors in drawer-style storage areas to ensure that the temperature in every storage area can be precisely controlled. For example, the refrigerating compartment controls the temperature at 0-4°C for storing vegetables, fruits, and other ingredients; the freezing compartment controls the temperature below -18°C for storing meat, seafood, etc.; the variable temperature compartment can be flexibly adjusted between -18°C and 5°C according to ingredient needs, realizing functions such as "soft freezing" (e.g., -7°C) to facilitate users to take out meat for cooking at any time. Currently, the temperature control accuracy of smart refrigerator temperature sensors can reach ±1°C, effectively extending the freshness period of ingredients.
Humidity sensors are mainly used for humidity control in the refrigerating compartment to avoid ingredient spoilage due to water loss. Different ingredients have different humidity requirements. For example, leafy vegetables require a high-humidity environment (85%-95% RH), while dried goods and nuts require a low-humidity environment (45%-55% RH). High-end refrigerators adopt "dry and wet separate storage" technology, dividing the refrigerating compartment into high-humidity and low-humidity zones through independent humidity sensors and humidity control modules to meet the storage needs of different ingredients.
Ingredient identification sensors automatically identify the type and freshness of ingredients through optical or multispectral technology. Optical sensors are mainly based on the principle of image recognition. Built-in cameras capture images of the ingredients inside the refrigerator. Combined with AI algorithms, the sensors identify ingredient types (e.g., apples, bananas and beef), with a resolution usually at least 2 megapixels to ensure recognition accuracy.
The application of semiconductor gas sensors in refrigerators mainly focuses on the two needs of "odor detection" and "health monitoring." Semiconductor gas sensors can detect the concentration of odorous gases such as ammonia and hydrogen sulfide in real time. When the concentration exceeds the threshold, the deodorization function will be automatically activated (e.g., through an activated carbon filter or ultraviolet sterilization) to keep the air inside the refrigerator fresh. Some high-end refrigerators are also equipped with pesticide residue detection sensors, which detect pesticide residue components on the surface of ingredients (e.g., organophosphorus, carbamates), with a detection limit of no more than 0.1ppm. When pesticide residue exceeding the standard is detected, it will promptly alert the user to clean or process them, ensuring dietary safety.
In addition, some smart refrigerators are also equipped with door sensors to detect whether the refrigerator door is closed tightly, avoiding increased energy consumption and ingredient spoilage caused by cold air leakage; pressure sensors are used in drawer-style storage areas to judge the storage volume of ingredients by detecting pressure changes in the drawer. When the storage volume is too large, it will remind users to place ingredients reasonably to ensure smooth cold air circulation.
Sensor Configuration and Application Scenario Implementation The number of sensor configurations in refrigerators is closely related to their functional complexity: entry-level three-door refrigerators, due to relatively basic functions, are usually configured with 6-8 sensors, including 3-4 temperature sensors, 1-2 humidity sensors, 1 door sensor, and 1 semiconductor gas sensor; while high-end French multi-door refrigerators, with multiple functions such as ingredient identification, zoned humidity control, and pesticide residue detection, can be configured with up to 10-12 sensors. In addition to basic temperature and humidity sensors, they also include ingredient identification sensors, pesticide residue detection sensors, pressure sensors, etc.
3. Washing Machines: Achieving a Balance between "Precise Washing" and "Garment Care"
Through sensor technology, washing machines achieve precise judgment of clothing volume, water quality, and garment materials, thereby optimizing the washing process, minimizing garment wear while ensuring cleaning effectiveness, and solving problems of traditional washing machines such as "less clothes but more water," "fixed washing time," and "severe garment wear."
Core Sensor Types and Application Functions Water level sensors determine the "matching relationship between clothing volume and water level" by detecting the water level height in the washing tub to automatically adjust the water inlet volume. Currently, the mainstream washing machine water level detection mostly adopts pressure sensors. Its working principle is: the bottom of the washing tub is connected to the sensor. After clothes are put into the washing tub, the water inlet volume increases, and the pressure in the washing tub increases accordingly. The sensor converts the detected pressure change into an electrical signal and transmits it to the main control chip. The chip judges the clothing volume based on the electrical signal and then controls the water inlet volume. The accuracy of the water level sensor can reach ±5mm. This accuracy ensures a precise match between the water inlet volume and clothing volume, avoiding water waste caused by "less clothes but more water," and also preventing incomplete washing caused by "more clothes but less water."
The main function of temperature sensors in washing machines is to control the water temperature for heated washing to meet the washing needs of different garment materials and stain types. Currently, the heating range of washing machines is usually 30°C-90°C; washing machines with drying functions are equipped with 5%-15% RH humidity sensors to detect and control the dryness.
Vibration sensors are installed on the bracket of the washing tub. When the vibration amplitude exceeds the threshold, the signal is transmitted to the main control chip. The chip adjusts the dehydration speed or starts the "redistribute clothes" program to make the clothes evenly distributed on the inner wall of the washing tub, thereby reducing the vibration amplitude and ensuring the stable operation of the dehydration process. Some high-end washing machines are configured with multiple vibration sensors to detect vibrations in different directions of the washing tub, further improving the accuracy of vibration detection.
Turbidity sensors emit light of a specific wavelength through the washing water and determine the concentration of dirt in the water based on the transmittance or scattering rate of the light. The lower the transmittance and the higher the scattering rate, the higher the dirt concentration. When the turbidity drops below the threshold, it feeds back to the main control chip and stops washing, entering the rinsing stage; if the dirt concentration is high, it automatically extends the washing time or increases the number of rinses to ensure the clothes are washed clean. Currently, the sensitivity of mainstream turbidity sensors can identify dirt concentrations above 50ppm, enabling precise judgment of the washing status of clothes.
In addition, some high-end washing machines are also equipped with garment material sensors and ultraviolet sensors. Garment material sensors identify garment materials (e.g., cotton, linen, wool, silk) by detecting parameters such as the conductivity and air permeability of the garments, and automatically match the best washing program according to the material characteristics; ultraviolet sensors are used for sterilization functions, ensuring the effectiveness of the sterilization process by detecting the intensity of ultraviolet rays, avoiding incomplete sterilization caused by insufficient ultraviolet intensity.
Sensor Configuration and Application Scenario Implementation The number of sensor configurations in washing machines varies by type and function: front-loading washing machines, due to more complex functions, are usually configured with 4-6 sensors, including 1 water level sensor, 1 temperature sensor, 2 vibration sensors (detecting horizontal and vertical vibrations respectively), 1 turbidity sensor, and 1 garment material sensor; top-loading washing machines have relatively simple functions, and the number of sensor configurations is usually 3-4, including 1 water level sensor, 1 temperature sensor, 1 vibration sensor, and 1 turbidity sensor. Washing machines with drying functions add 1-2 humidity sensors.
4. Color TVs: Building an "Immersive" and "Health-Oriented" Viewing Experience
Smart color TVs realize adaptive adjustment of screen brightness and color, as well as eye health reminders through various sensors such as ambient light sensors, color temperature sensors, and human body distance sensors, making the viewing experience more comfortable and healthier.
Core Sensor Types and Application Functions Ambient light sensors automatically adjust the screen brightness by detecting the intensity of indoor ambient light, avoiding damage to the eyes caused by the screen being too bright or too dark. Ambient light sensors are usually installed on the screen bezel of the color TV, capable of collecting indoor light data in real time, with a measurement range generally 10-1000lux, covering various environmental scenarios from dim light at night to strong light during the day.
Color temperature sensors are used for the "color restoration calibration" of color TVs, ensuring that the colors displayed on the screen are closer to natural colors and enhancing the realism of the viewing experience. Currently, the accuracy of mainstream color TV color temperature sensors can reach ±200K, enabling precise capture of changes in ambient light color temperature and ensuring the accuracy of color restoration.
Human body distance sensors are used to detect the distance between the user and the color TV screen, issuing eye care reminders when the distance is too close to avoid vision decline caused by long-term close-range viewing. Infrared ranging technology is mostly adopted, with a detection distance range usually 0.5-3m. When the distance between the user and the screen is detected to be less than the set threshold (e.g., 0.5m), reminder information will pop up on the screen, or a voice warning will be issued; some high-end color TVs will also automatically reduce the screen brightness when the distance is too close, further reducing stimulation to the eyes. This function is especially suitable for families with children and can effectively cultivate good viewing habits for children.
Voice sensors realize the control of the color TV by collecting users' voice commands, such as changing channels, adjusting volume, searching for movies. Usually composed of an array of 2-4 silicon microphones, through beamforming technology, they can accurately capture users' voice commands while filtering out environmental noise to ensure the accuracy of voice recognition. Currently, the voice recognition accuracy of mainstream color TVs can reach over 95%, with a response time no more than 1s, enabling a smooth voice interaction experience.
In addition, some high-end color TVs are also equipped with gesture recognition sensors and gravity sensors. Gesture recognition sensors realize the control of the color TV by detecting users' gesture movements, such as waving to change channels and adjusting volume with gestures, further enhancing the convenience of interaction; gravity sensors are mainly used for the installation detection of color TVs. When the color TV is not installed firmly or tilts, it will issue an alarm to avoid safety accidents.
Sensor Configuration and Application Scenario Implementation The number of sensor configurations in smart color TVs is usually 3-5. The basic configuration includes 1 ambient light sensor, 1 color temperature sensor, 1 human body distance sensor, and 1 set of voice sensors (including 2-4 microphones); high-end color TVs add gesture recognition sensors on this basis, with the configuration quantity reaching more than 5.
In terms of application scenarios, the collaborative work of sensors makes the viewing experience of color TVs more aligned with user needs. For example, on a weekend afternoon, when a user is watching a movie in the living room and sunlight shines into the room through the window, the ambient light sensor detects the increase in ambient light intensity and automatically increases the screen brightness. The color temperature sensor simultaneously detects the increase in ambient light color temperature and adjusts the screen color temperature to 6000K to match the natural light color temperature, ensuring real and natural picture colors; when the user approaches the screen to debug the equipment, the human body distance sensor detects that the distance is less than 0.5m and immediately pops up a reminder message on the screen saying "Distance too close, please pay attention to eye health"; when the user wants to switch movies, there is no need to use a remote control. By directly saying "search for sci-fi movies," the voice sensor accurately captures the command and executes it, quickly presenting the relevant movie list to the user.
(II) Small Home Appliances
Small home appliances cover multiple scenarios such as the kitchen, environment, and personal care. Their intelligent upgrading focuses more on "convenience" and "precision." From the precise temperature control of rice cookers to the force reminders of electric toothbrushes, the application of sensor technology transforms small home appliances from "simple tools" to "caring assistants."
1. Kitchen Small Home Appliances: Precise Control for a Delicious Experience
Sensors enable kitchen small home appliances to accurately capture key parameters during the cooking process, realizing precise control of the cooking process and helping users easily cook delicious food.
Rice Cookers: Precise Control of Temperature and Pressure to Restore the Aroma of Wood-Fired Rice Smart rice cookers achieve precise control of the rice cooking process through the collaboration of temperature sensors and pressure sensors, solving problems such as "undercooked rice" and "mushy texture" in traditional rice cookers.
Temperature sensors are mainly used to monitor the temperature of the inner pot and control the temperature in different stages such as cooking and keeping warm. Usually, one is installed at the bottom of the inner pot and one at the top. When the inner pot temperature reaches 100°C, it indicates that the water has boiled, and the main control chip controls the heating device to reduce power and enter the "simmering" stage; when the temperature sensor at the top detects that the steam temperature drops (indicating that the water has basically evaporated), it judges that the rice is cooked and automatically switches to the keeping warm mode. Currently, the accuracy of smart rice cooker temperature sensors can reach ±1°C, enabling precise control of the temperature in each stage of rice cooking.
Pressure sensors are mainly used for the high-pressure rice cooking function. By increasing the pressure in the inner pot, the boiling point of water is raised, thereby shortening the rice cooking time and making the rice softer and more glutinous. The pressure sensor is installed on the sealing cover of the inner pot to monitor the pressure change in the inner pot, with a range usually 0-1.2atm.
Microwave Ovens: Humidity Detection to Avoid Dry Burning of Food Smart microwave ovens achieve precise timing and moisture retention for food heating by configuring humidity sensors and temperature sensors, ensuring heating effectiveness.
The humidity sensor is installed at the top of the microwave oven cavity, with a measurement range usually 30%-80% RH. When food is heated, water evaporates to produce water vapor, and the humidity in the cavity rises. The humidity sensor transmits the detected data to the main control chip; when the humidity reaches the set threshold, it indicates that the food has been heated to a suitable temperature, and the chip controls the microwave oven to stop heating to avoid excessive heating leading to moisture loss.
The temperature sensor is installed on the side wall of the cavity. When the cavity temperature exceeds the set value (e.g., 200°C), it feeds back a signal to the main control chip, and the chip controls the heating device to reduce power or pause heating, resuming heating after the temperature drops to a safe range. In addition, the data from the temperature sensor can also assist the humidity sensor in judging the heating status of the food, improving the accuracy of heating control.
Dishwashers: Water Quality Monitoring to Optimize the Cleaning Process Smart dishwashers achieve precise judgment of the cleaning water level, water temperature, and the dirtiness of tableware through the collaborative work of water level sensors, temperature sensors, and turbidity sensors, thereby optimizing the cleaning process and reducing energy consumption while ensuring cleaning effectiveness.
The water level sensor is installed at the bottom of the dishwater tank, with an accuracy of up to ±3mm. When the water level in the tank reaches the set value, the sensor feeds back a signal to the main control chip, and the chip controls the water inlet valve to close and stop water inlet; during the cleaning process, if the water level drops due to evaporation or leakage, the sensor will detect it and control the water inlet valve to open again to replenish the water volume.
The temperature sensor is installed near the cleaning spray arm to monitor the temperature of the cleaning water in real time, improving cleaning effectiveness and sterilization ability. When the water temperature is below 60°C, the heating device automatically starts; when the water temperature reaches 70°C, the heating device stops working to ensure the water temperature remains stable in the optimal cleaning range.
The turbidity sensor is installed at the drain outlet of the dishwasher. When the cleaning water passes through the drain outlet, the sensor emits light through the water flow and judges the concentration of oil and food residue in the water based on the scattering rate of the light; if the concentration is high, it indicates that the tableware is heavily soiled, and the chip will automatically extend the cleaning time and add one rinse; if the concentration is low, it indicates that the tableware is relatively clean, and the chip will shorten the cleaning time and reduce the number of rinses.
2. Environmental Small Home Appliances: Precise Adjustment for a Comfortable Environment
Environmental small home appliances rely on sensors for precise monitoring of environmental parameters to achieve "adjustment on demand," creating a comfortable and healthy indoor environment for users. Examples include air purifiers improving air quality, humidifiers adjusting air humidity, and electric fans adjusting indoor wind speed.
Air Purifiers: Real-Time Monitoring for Efficient Purification Smart air purifiers achieve comprehensive monitoring of indoor air quality and precise control of purification effects through the collaborative work of PM2.5 sensors, VOC sensors, and temperature and humidity sensors.
PM2.5 sensors are usually based on the principle of laser scattering. By emitting laser light to irradiate particulate matter in the air and calculating the PM2.5 concentration based on the intensity of the scattering signal of the particulate matter to the laser, the accuracy can reach ±5μg/m³; when the concentration exceeds the set value (e.g., 35μg/m³), the air purifier automatically starts or increases the purification gear to accelerate the removal speed of particulate matter; when the concentration drops to a safe range (e.g., ≤35μg/m³), it automatically reduces the gear or shuts down to save energy.
VOC sensors are used to detect the concentration of volatile organic compounds such as formaldehyde, benzene, and toluene indoors, with a response time usually no more than 5s, enabling quick capture of changes in indoor air quality. After users newly decorate their houses or buy new furniture, the indoor VOC concentration may exceed the standard. The VOC sensor will immediately issue an alarm after detection and trigger the strong purification mode of the air purifier; at the same time, by displaying VOC concentration data in real time, it allows users to intuitively understand the health status of indoor air.
Although temperature and humidity sensors do not directly participate in the purification process, they can provide auxiliary basis for the operation of the air purifier. For example, in a high-humidity environment, the filter of the air purifier is easy to get damp and moldy. When the temperature and humidity sensor detects that the humidity exceeds 80% RH, it will remind users to replace the filter in time; at the same time, some air purifiers combine temperature and humidity data to provide users with comprehensive evaluation and improvement suggestions for the indoor environment.
Humidifiers: Humidity Control to Avoid Over-Humidification Smart humidifiers achieve precise humidity control and water shortage protection through the collaborative work of humidity sensors and water level sensors, adjusting indoor humidity to a comfortable range. They also have the function of automatically starting and shutting down at a set target humidity, avoiding the risk of dry burning without affecting users' sleep.
The humidity sensor is the core component of the smart humidifier, used to monitor indoor air humidity in real time, with an accuracy of up to ±5% RH. Users can set the target humidity according to their needs (e.g., 50% RH). The humidity sensor compares the detected actual humidity with the target humidity. When the actual humidity is lower than the target humidity, the humidifier automatically starts, increasing indoor humidity through ultrasonic atomization or evaporation; when the actual humidity reaches the target humidity, the humidifier automatically shuts down to avoid over-humidification.
The water level sensor is installed at the bottom of the water tank. When the water level in the tank is below the set threshold, the sensor feeds back a signal to the main control chip, and the chip controls the humidifier to stop working and issues a water shortage alarm through an indicator light or buzzer, reminding users to add water to avoid damage to the humidifier due to dry burning. Some high-end humidifiers can also push water shortage reminders to users via mobile APP, making it convenient for users to remotely understand the status of the humidifier.
Electric Fans: Smart Start/Stop for Air Supply on Demand Smart electric fans realize automatic adjustment of wind speed and start/stop according to the ambient temperature and human presence status through the collaborative work of temperature sensors and human body infrared sensors, solving problems of traditional electric fans such as "continuous operation when no one is present" and "fixed wind speed."
Temperature sensors collect indoor temperature data in real time and transmit it to the main control chip. The chip automatically adjusts the wind speed according to preset rules to ensure that users are always in a comfortable environment.
Human body infrared sensors are used to detect whether there is someone indoors and can also recognize the activity status of the human body through AI algorithms. When it detects that the user is sleeping, it automatically reduces the wind speed and gradually shuts down to prevent the user from catching a cold at night, maintaining comfortable cool air while reducing energy consumption.
3. Personal Care Small Home Appliances: Caring Protection for Health Assurance
Smart personal care small home appliances achieve precise monitoring of human status and equipment operating status through sensor technology, ensuring a safe and comfortable usage process.
Hair Dryers: Temperature Control to Avoid Hair Damage Smart hair dryers achieve precise control of the air outlet temperature and air volume through the collaboration of temperature sensors and wind speed sensors, with an accuracy of up to ±3°C, caring for hair health.
The wind speed sensor is installed at the air inlet of the hair dryer. By detecting the air flow velocity, it judges the air volume and controls the heating device to stop working to avoid overheating and damage to the hair dryer due to insufficient air volume. During the drying process, if the hair accidentally blocks the air inlet, the wind speed sensor detects a sharp drop in air volume and immediately issues a buzzer alarm, while the heating device stops working to prevent the hair dryer from overheating; after the user cleans the air inlet and the wind speed returns to normal, the hair dryer automatically resumes working.
Electric Toothbrushes: Pressure Reminder to Protect Gum Health Smart electric toothbrushes achieve precise control of brushing force and vibration frequency through the collaboration of pressure sensors and vibration sensors, caring for oral health.
The pressure sensor is installed at the connection between the brush head and the brush handle to detect the user's brushing force, with a range usually 0-3N. When the user's brushing force is too large (exceeding 1.5N), it immediately reduces the vibration frequency of the brush head; when the brushing force returns to normal, the vibration frequency also recovers, ensuring cleaning effectiveness while avoiding damage to the gums due to excessive force.
The vibration sensor is used to monitor the vibration frequency of the brush head to ensure stable cleaning effectiveness. The vibration frequency of mainstream smart electric toothbrushes is usually 30,000-40,000 times/minute. The vibration sensor monitors the vibration frequency of the brush head in real time. When the frequency is lower than the set value, it indicates that the battery is low or the brush head is worn. The sensor feeds back a signal to the chip, reminding the user to charge or replace the brush head through an indicator light.
Massagers: Force Adjustment to Adapt to Different Needs Smart massagers achieve precise adjustment of hot compress temperature and massage force through the collaborative work of temperature sensors and pressure sensors, providing users with a personalized massage experience.
Temperature sensors are used to control the hot compress temperature of the massager to ensure hot compress effectiveness and usage safety. The hot compress temperature of the massager is usually controlled between 40°C-45°C. This temperature can effectively promote blood circulation and relieve muscle fatigue without scalding the skin. The temperature sensor is installed inside the massage head to monitor the hot compress temperature in real time. When the temperature is below 40°C, the heating device automatically starts; when the temperature is above 45°C, the heating device stops working to ensure the temperature remains stable in a comfortable range.
Pressure sensors are used to detect the contact pressure between the massager and the human body, thereby adjusting the massage force to adapt to the tolerance of different users. Massagers are usually configured with 2-3 pressure sensors, installed on different massage heads respectively. They judge the user's tolerance based on pressure data and automatically adjust the vibration amplitude and pressure.
II. Market Status and Scale Analysis
Given the steady advancement of home appliance intelligence, sensors, as core components, have seen their market scale steadily expanding, and the industrial chain segment pattern is gradually becoming clear. Both the global and Chinese markets show the characteristics of "strong demand and local rise." The demand for sensors varies significantly across different home appliance categories. The breakthrough in upstream chip technology and the intelligent upgrading demand of downstream home appliance manufacturers have formed a positive interaction, driving the sustained development of the market.
(I) Overall Market Scale: Global Growth, Fastest in China
In recent years, the global smart home appliance market has maintained rapid growth, driving the sustained increase in demand for smart home appliance sensors. According to data from market research firm Grand View Research, the global home appliance sensor market scale reached 18.76 billion US dollars in 2023 and is expected to reach as high as 25 billion US dollars in 2025. The compound annual growth rate (CAGR) from 2020 to 2025 reached 12.3%, and it is expected to exceed 30 billion US dollars by 2026. This is mainly due to the increase in the penetration rate of global smart home appliances and the growth in consumers' demand for intelligent and healthy home appliances.
From the perspective of regional markets, the Asia-Pacific region is the largest market for global home appliance sensors, with a market share of 52.7% in 2023, among which China, Japan, and South Korea are the main contributors. As the world's largest home appliance producer and consumer, China's home appliance sensor market scale has grown particularly rapidly. According to data from the China Electronic Components Industry Association, the market scale of China's local home appliance sensors reached 48.6 billion RMB in 2023 and is expected to reach 65 billion RMB in 2026, with a compound annual growth rate of 15.8%, higher than the global average. This growth is mainly due to the wave of intelligent upgrading of Chinese home appliance enterprises and the acceleration of technological breakthroughs and domestic substitution processes of local sensor enterprises.
From the perspective of market competition pattern, the global home appliance sensor market is still dominated by international suppliers. International giants such as Bosch, STMicroelectronics, Texas Instruments (TI), and Sony occupy about 60% of the global market share with their technological advantages and brand influence. These enterprises have profound accumulation in sensor chip design and manufacturing processes. Their products have high precision and strong stability, and are mainly supplied to globally renowned home appliance enterprises such as Samsung, LG, Haier, and Midea.
Chinese local sensor enterprises have developed rapidly in recent years. Enterprises such as Hanwei, GoerTek, Macrosen, MemSensing, and Inovance have gradually occupied a place in the market, and some enterprises have achieved breakthroughs in the high-end market in specific fields. For example, Hanwei and Macrosen gas sensors are steadily expanding in the home appliance market such as air purifiers and refrigerators. In 2025, the market share of local enterprises has increased to 35%, an increase of 12 percentage points compared to 2020, achieving significant results in domestic substitution.
(II) Segmented Market: Large Home Appliances as the Mainstay, Significant Increment in Small Ones
The demand for sensors in different home appliance categories shows significant differentiation characteristics. Large home appliances remain the core source of sensor demand; while small home appliances, relying on innovation and consumption upgrading, have become an important driving force for demand growth.
- Among large home appliances, air conditioners, refrigerators, and washing machines contributed a total of 58% of the total demand for home appliance sensors in 2023, with air conditioners ranking first with a share of 22%. The intelligent upgrading of air conditioners focuses on "comfort" and "health." In addition to basic temperature and humidity sensors, the configuration rate of air quality sensors such as PM2.5 and VOC has increased from 30% in 2020 to 75% in 2024. The number of sensors configured in a single high-end air conditioner is 3-5 more than that of ordinary models, directly driving the annual growth rate of air conditioner sensor demand to reach 18%. The intelligent upgrading of refrigerators in the application of new sensors such as ingredient identification and pesticide residue detection has increased the cost of refrigerator sensors by more than 50% compared to ordinary models. In 2024, the demand increased by 25% year-on-year compared to 2023, becoming the fastest-growing segmented market in the refrigerator field. The number of sensor configurations in front-loading washing machines is generally 2-3 more than that in top-loading washing machines. In 2024, the demand for washing machine sensors increased by 15% year-on-year, among which high-end front-loading models contributed 60% of the increment.
- In the field of small home appliances, kitchen small home appliances and environmental small home appliances accounted for a total of 32% of the total demand for home appliance sensors in 2024. Among kitchen small home appliances, the intelligent upgrading of rice cookers, microwave ovens, and dishwashers has driven the demand for temperature, pressure, and turbidity sensors. The sensor cost of smart rice cookers has increased by 30% compared to traditional models. In 2024, the demand for kitchen small home appliance sensors increased by 20% year-on-year. Environmental small home appliances have benefited from the health consumption boom. The sensor configuration rate of air purifiers and humidifiers has reached 100%. The penetration rate of PM2.5 sensors in air purifiers has increased from 65% in 2020 to 98% in 2024, driving the demand for environmental small home appliance sensors to increase by 22% year-on-year. Personal care small home appliances have become a new highlight of growth. The rise of categories such as smart electric toothbrushes and massagers has driven a surge in demand for pressure and vibration sensors. In 2023, the demand for personal care small home appliance sensors increased by 35% year-on-year, making it the fastest-growing field among all segmented categories.
- Price differences are obvious, showing distinct hierarchical characteristics. The unit price of basic sensors (such as temperature and humidity sensors) is usually 5-20 RMB, mainly applied to mid-to-low-end home appliances; the unit price of mid-to-high-end sensors (such as ingredient identification and pesticide residue detection sensors) can reach 50-200 RMB, concentrated in high-end models. Taking refrigerators as an example, the sensor cost of high-end French multi-door refrigerators can reach 200-300 RMB, accounting for 5%-8% of the total cost of the refrigerator; while the sensor cost of ordinary three-door refrigerators is only 50-80 RMB, accounting for less than 2%. This price difference also leads to high-end home appliances becoming the main source of profit for sensor enterprises.
(III) Industrial Chain Pattern: High Upstream Barriers, Midstream and Downstream Collaborative Innovation
The industrial chain of smart home appliance sensors is divided into three segments: upstream (chips, sensitive components), midstream (sensor modules), and downstream (home appliance OEMs). The technical thresholds and competition patterns of each segment vary significantly, forming an industrial ecology of "upstream monopoly, midstream competition, and downstream dominance."
The upstream is the core component supply segment with extremely high technical barriers, and the global market is dominated by international suppliers. Sensor chips are the core determining the precision and stability of sensors. Their R&D requires profound accumulation of semiconductor technology. Currently, international giants such as Infineon, Sony, and Texas Instruments (TI) occupy more than 80% of the global sensor chip market share.
The midstream is sensor modules with a relatively lower technical threshold, and domestic enterprises compete fiercely. Module manufacturing mainly involves processes such as packaging and calibration. Domestic enterprises such as Macrosen and MemSensing have occupied a dominant position in the domestic market through scaled production and customized services. The focus of competition in this segment is concentrated on cost control, delivery cycle, and customization capabilities, with a relatively low profit level, accounting for only 20%-30% of the industrial chain profit.
The downstream is the home appliance OEM application segment, where domestic enterprises occupy a dominant position, and the demand traction effect is significant. Domestic home appliance giants such as Haier, Midea, Gree, and Xiaomi, with their huge production scale, have strong bargaining power over midstream module enterprises.
Currently, the entire industrial chain presents a pattern of "upstream monopoly, midstream competition, and downstream dominance." The upstream chip technology bottleneck, insufficient midstream calibration efficiency, and industrial chain data silos are the main challenges currently faced. To enhance product competitiveness and supply chain security, downstream enterprises have actively carried out joint R&D with sensor enterprises, co-building joint laboratories to achieve collaborative innovation across the entire industrial chain.
The successful cooperation between Haier and Hanwei Technology has provided exploration experience for the collaborative development of the home appliance sensor industrial chain, forming three characteristics: first, the R&D model of "scenario demand driving technological innovation" is more efficient. The specific technical indicators proposed by the downstream make the upstream R&D direction clear, avoiding the disconnection between technological R&D and market demand, and greatly shortening the R&D cycle of new products. Second, "data sharing breaks the barrier between production and use technology," shifting from "blind trial and error" to "precise breakthrough," improving innovation efficiency and providing effective support for the performance optimization of sensors. Third, forming an "interest sharing mechanism" to achieve cost reduction and profit increase, forming an interest community of "one prospers, all prosper." This model can stimulate the innovation incentives of both parties more than a simple transaction relationship, driving the sustained upgrading of the industrial chain.
III. Future Development Trends of Home Appliance Sensors
Given the steady progress of technologies such as IoT and AI, and the sustained upgrading of consumers' demand for smart home appliances, smart home appliance sensors are advancing towards the direction of "high precision, miniaturization, low power consumption, integration, and intelligence." At the same time, the collaborative innovation of the industrial chain will be further deepened, and the domestic substitution process will accelerate, injecting stronger momentum into the development of the smart home appliance industry.
(I) Technological Trends: Multi-Dimensional Upgrading to Break Through Performance Bottlenecks
- Precision and stability steadily improve to meet high-end demands In the future, sensors will achieve performance breakthroughs through material innovation and process optimization, with precision and stability further improving. In terms of materials, new nano-materials and ceramic materials will be widely used in sensor manufacturing. For example, using nano-metal oxides as sensitive materials for gas sensors can reduce the VOC detection limit from 0.1ppm to 0.01ppm while improving the anti-interference ability of the sensor; using zirconia ceramics as the packaging material for temperature sensors can enable the sensor to maintain an accuracy of ±0.1°C in the extreme temperature range of -50°C to 150°C. In terms of processes, MEMS manufacturing processes will upgrade towards "micro-nano," with lithography precision improving from the current 0.1 microns to 0.05 microns, making the sensor chip smaller in volume and more stable in performance. For example, the area of the temperature sensor chip used in smart watches can be reduced to less than 1 square millimeter, while power consumption is reduced by 30%.
- Miniaturization and low power consumption go hand in hand to adapt to miniaturized home appliances Given the rise of segmented categories such as personal care small home appliances and portable home appliances, the "miniaturization" and "low power consumption" of sensors have become important development directions. On the one hand, by integrating multiple sensor functions on a single chip through chip integration technology, a "multi-in-one" sensor module is realized. For example, integrating temperature, humidity, and VOC sensors into a module with a size of only 2mm×2mm greatly saves the internal space of home appliances, adapting to small home appliances such as electric toothbrushes and mini humidifiers. On the other hand, adopting low-power chip design and energy-saving algorithms to reduce the power consumption of sensors. For example, the power consumption of the pressure sensor in smart rice cookers can be reduced from the current 10mA to 2mA. Combined with battery power supply, wireless monitoring can be realized, providing possibilities for the modular design of home appliances. In addition, the application of energy harvesting technology will realize the "passive" nature of sensors. For example, using the vibration energy generated during the operation of home appliances to power sensors, completely getting rid of the dependence on batteries.
- Intelligent upgrading, from "data collection" to "decision support" Combined with AI algorithms, sensors have data processing and decision support capabilities through edge computing, becoming an intelligent terminal of "perception + computing." For example, the air quality sensor for air conditioners will have built-in AI algorithms. It can not only detect PM2.5 and VOC concentrations but also predict air quality changes based on concentration trends and activate the purification function in advance; the ingredient identification sensor of refrigerators, through AI image recognition technology, can not only identify ingredient types but also recommend recipes based on users' dietary habits and automatically generate shopping lists. This intelligent upgrading transforms sensors from "data providers" to "decision participants," further enhancing the autonomous service capabilities of smart home appliances.
- Multi-sensor fusion to improve scenario adaptation capabilities Through multi-sensor fusion technology, the collected data of different types are complemented to improve the adaptation capabilities of smart home appliances to complex scenarios. For example, smart washing machines will integrate garment material sensors, water quality sensors, turbidity sensors, and ultraviolet sensors. They can not only adjust the washing program according to garment materials and dirtiness but also detect water hardness and automatically add the appropriate dose of detergent, while ensuring sterilization effectiveness through ultraviolet sensors; smart color TVs will integrate ambient light sensors, color temperature sensors, human body distance sensors, and gesture recognition sensors to realize adaptive adjustment of screen parameters and multi-modal interaction, providing users with a more convenient and comfortable viewing experience. The core of multi-sensor fusion technology is the optimization of data fusion algorithms. Through the integration and analysis of multi-source data, the detection errors of a single sensor are eliminated, improving the accuracy of judgment.
(II) Market Trends: Diversified Demand, Accelerated Domestic Substitution
- High-end home appliances become the core engine for demand growth Given the upgrading of residents' consumption, high-end smart home appliances drive the rapid growth of demand for mid-to-high-end sensors. According to data from the China Household Electrical Appliances Association, the market scale share of China's high-end smart home appliances reached 28% in 2023 and is expected to exceed 40% in 2026 and reach 50% in 2030. High-end home appliances have higher requirements for the configuration quantity and performance of sensors. For example, the number of sensors configured in high-end French multi-door refrigerators is 2-3 times that of ordinary refrigerators, and they mostly use mid-to-high-end sensors such as high-precision ingredient identification and pesticide residue detection, which will drive the home appliance sensor market to transform towards "high-end." At the same time, the popularization of consumption concepts such as health, environmental protection, and energy saving will give rise to more new sensor demands, such as electric energy sensors for monitoring home appliance energy consumption and ion sensors for detecting heavy metal content in water quality.
- Domestic substitution breaks through from "mid-to-low-end" to "high-end" Driven by both policy support and technological R&D, the domestic substitution process of domestic sensor enterprises will accelerate breakthroughs. On the one hand, breakthroughs in core technologies such as MEMS sensor chips and precision calibration processes by local enterprises will break the monopoly of international suppliers. For example, Macrosen's infrared chips have been produced on a large scale and exported in large quantities. On the other hand, the "domestic substitution" strategy of downstream home appliance enterprises will provide more opportunities for local sensor enterprises. Home appliance giants such as Haier and Midea have set up "special procurement for domestic sensors," giving priority to purchasing certified local products.
- Emerging markets become new space for growth Given the advancement of the "Belt and Road" initiative, Chinese smart home appliance enterprises are deepening their layout in emerging markets such as Southeast Asia, Africa, and Latin America, driving the overseas expansion of local home appliance sensor enterprises. These emerging markets have a low penetration rate of home appliances, strong demand for intelligent upgrading, and high price sensitivity to sensors. Local enterprises are expected to quickly occupy market share with their cost advantages. For example, Macrosen's infrared sensors have entered the smart home supply chain in Central Asia, Europe, and Southeast Asia in partnership with Huawei, with sales increasing by 45% year-on-year. By cooperating with local home appliance enterprises, they further expand overseas markets and enhance global competitiveness. Hanwei Technology's gas sensors have been applied to air purifier products in Africa, gaining local market recognition with high cost-effectiveness.
Conclusion
Looking ahead, the iteration trend of home appliance sensor technology ultimately points to human-oriented smart life scenarios. From precise perception to proactive service, its development will continue to reconstruct the interaction relationship between humans and home appliances, providing a technical cornerstone for consumption upgrading. The growth in demand for high-end home appliances and domestic substitution will become the core driving force for market growth, and the deepening of industrial chain collaboration will drive the reconstruction of the industrial ecology. Given the breakthroughs of local enterprises in core technologies, the improvement of industrial chain collaboration mechanisms, and the strengthening of policy support, China's home appliance sensor industry is expected to achieve a leap from "following" to "leading," providing solid support for the high-quality development of the smart home appliance industry.
For practitioners in the industrial chain, they should seize the opportunities of technological upgrading and market transformation. Upstream enterprises should focus on breakthroughs in core technologies, midstream enterprises should strengthen scaled and customized capabilities, and downstream enterprises should play the role of demand traction, building a healthy industrial ecology of development through collaborative innovation; for consumers, the progress of sensor technology will bring smarter, healthier, and more convenient home appliance products, steadily improving the quality of life. Driven by the dual forces of technological innovation and market demand, the smart home appliance sensor industry will surely open up broader development space and drive the smart home appliance revolution to a new height.
Author | Guo Yuansheng, Deputy Director of the Science and Technology Committee of the Central Committee of the Jiusan Society, Executive Vice Chairman of the China Sensor and IoT Industry Alliance Editor | Yang Pengyue Art Editor | Malia Supervisor | Zhao Chen