Review of the DFRobot Fermion MEMS Gas Sensor Series

The DFRobot Fermion MEMS series gas sensor uses MEMS technology to manufacture micro hotplates on a Si substrate, and the gas-sensitive material used is a metal oxide semiconductor material with low conductivity in clean air. When the detected gas is present in the ambient air, the conductivity of the sensor changes, and the higher the concentration of the gas, the higher the conductivity of the sensor. The structure of this sensor series is robust, and a simple circuit can be used to convert the change in conductivity into an output signal that corresponds to the concentration of the gas. Its small size and low power consumption also make it easy to integrate with other devices.

This series includes a variety of gas sensors, such as HCHO, CO, CH4, VOC, NH3, H2S, EtOH, Smoke, Odor, H2, NO2 , suitable for applications such as environmental monitoring, industrial production, and indoor safety. The odor and C2H5OH sensors are suitable for mini breath analyzers, breath gas analyzers, and more. This sensor series can be used in various fields such as environmental monitoring, indoor safety, industrial production, fire early warning, and smart homes.

Figure: Fermion: MEMS Carbon Monoxide CO Gas Detection Sensor

Product Features:

1. Multiple gas detection: HCHO, CO, CH4, NH3, H2S, Smoke, H2, NO2, VOC, Odor, and C2H5OH.

2. Rapid response and recovery: Response time is as fast as 5 seconds.

3. Analog output: The sensors in this series provide analog output, which makes them easy to integrate with other devices.

4. Small size and low power consumption: The compact size of these sensors (only 13x13x2.5mm) and low power consumption (approximately 0.45W) make them suitable for mobile and battery-powered devices.

5. Low heat emission: These sensors emit less heat, making them safer to use.

6. Integration: These sensors can be used individually or in combination with other sensors to create a flexible system that can meet a wide range of gas detection needs. By connecting them to an embedded system with a simple circuit, they can be easily deployed to various applications and provide a more comprehensive solution for different scenarios.

(A sensor array comprising Fermion MEMS series sensors is utilized to detect fruit spoilage.)

Actual Test: (Control Arduino Uno)

I. Gas detection in trash cans (H2S, H2)

(credit: Pexels)

When testing the H2S and H2 sensors near the trash can in the kitchen, it was found that the sensitivity of the sensor is relatively high, and it can accurately detect changes in the concentration of H2S and H2 gases in the trash can. When the trash can cover is opened, the output voltage value instantly increases, and when the cover is closed, the voltage value quickly decreases. This indicates that the H2S and H2 sensors are very suitable for detecting heavy odors in trash cans and are suitable for portable and fixed odor monitors and detectors.

Note: This series of sensors is suitable for qualitative measurements, not quantitative measurements.

II. Exhaust gas detection in cars (NO2)

(Credit: Pexels)

When placing the NO2 sensor in the car's tailpipe, the reading of the sensor increases with the increase of the exhaust gas emissions as the car starts. The NO2 sensor can also be used to monitor air quality in the industrial field, such as exhaust gas emission monitoring in industrial scenes, and the production of portable and fixed nitrogen dioxide detectors.

Note: The module needs to be preheated for about 3 minutes each time it is powered on to ensure normal testing after the module is fully stable.

III. Gas leakage detection (CH4)

(Credit: Pexels)

The CH4 gas sensor is one of the MEMS sensor series and is a highly sensitive methane gas sensor. In the test, when placing the sensor in the kitchen, and turning on the gas stove, it can be found that it is very sensitive to gas.

(CH4)

Note: Please avoid the sensor circuit from splashing water or soaking in water, which may cause a decrease in the sensor's sensitivity.

IV. Precision fertilization (NH3)

When testing the NH3 sensor near the soil that has just been fertilized, it was found that the sensor can detect changes in the concentration of NH3 in the soil. During fertilization, the concentration of NH3 rises sharply for a short period of time, and within a few hours after fertilization, the concentration of NH3 gradually decreases. The NH3 sensor can detect these changes sensitively. This indicates that the NH3 sensor is very suitable for ventilation control in the agricultural breeding industry, gas detection in refrigerators, and ammonia leakage detection in cold storage warehouses.

Note: The sensitivity and response speed of the sensor are affected by environmental factors such as temperature and humidity, so attention should be paid to environmental conditions when using it.

V. Perfume gas detection (VOC, C2H5OH)

(Credit: Pexels)

Using multiple perfume detection ethanol sensors, for multiple perfumes, the sensors show similar voltage value curves. The perfume has a strong adsorption capacity and the chamber needs to be cleaned with a fan after detection. It is suitable for indoor air quality monitoring, application detection of consumer electronic products such as mobile phones and computers, and also suitable for breathalyzers, indoor smoke alarms, etc.

(VOC)

Note: Adsorptive gases need to clean the chamber.

VI. Indoor Formaldehyde Gas Detection (Formaldehyde CH2O)

(credit: Pexels)

During the process of house decoration, a large amount of formaldehyde gas is usually accompanied. It is an organic compound, colorless, and has an irritant gas that has an irritating effect on human eyes and nose and poses great harm to the human body. By placing the sensor next to the painted wall, the concentration of formaldehyde gas can be detected very sensitively. Compared with clean air, significant differences can be seen, reminding people to take timely measures to ventilate indoors, thus better protecting people's health.

Attention: The sensor is suitable for qualitative measurement rather than quantitative measurement. If precise quantitative measurement is required, it is recommended to use other more accurate sensors.

VII. Fire Warning (SMOKE, CO)

(credit: https://atticconstruction.com/blog/5-electrical-hazards-in-your-attic/)

CO and Smoke sensors can be used in fire warning systems to detect fires early and take timely measures. The CO sensor can detect the concentration of carbon monoxide, while the Smoke sensor can detect the concentration of smoke. The two sensors can be used in combination to improve accuracy and reliability. In the fire warning system, the CO sensor can detect the concentration of carbon monoxide produced during a fire. When the concentration exceeds the set threshold, the system will automatically trigger an alarm to remind people to take action. The smoke sensor can detect the concentration of smoke produced during a fire. When the concentration of smoke exceeds the set threshold, the system will also automatically trigger an alarm.

Testing CO and Smoke sensors with burning paper:

(Smoke)

(Smoke)

Summary:

DFRobot Fermion MEMS series gas sensors can detect a variety of gases and are suitable for environmental monitoring, indoor safety, industrial production, fire warning, smart homes, and health monitoring. Due to their small size, light weight, and low heat generation, they can be easily applied to various portable or embedded devices. When using this sensor, pay attention to its qualitative measurement characteristics and the impact of environmental conditions on sensitivity and response speed.

If you are interested in the DFRobot Fermion MEMS series sensors mentioned above, please check the product link.

More detailed product information