At the forefront of scientific exploration, electrochemical sensing is an indispensable and adaptable tool that influences various industries. From life sciences and environmental sciences to industrial materials and food processing, the ability to quantify chemicals can provide a deeper understanding of things, thereby improving safety, efficiency, and awareness.
In this advanced era of interconnected technology, the importance of low-power and high-precision electrochemical sensors cannot be overemphasized. In our homes, through interconnected devices, we can monitor the quality of air, water, and soil for plants. In the industrial sector, the demand is even greater. Intelligent medical devices (including wearable devices) improve understanding of diseases and enhance the quality of care by continuously monitoring patients' vital signs both inside and outside medical institutions in real-time, bringing healthcare into the 21st century.
Similarly, with the widespread application of Industry 4.0 in manufacturing and industrial automation, many industries have deployed a large number of perception node networks to improve efficiency and security. Sensors can monitor toxic gases generated in various industrial processes and enable feedback systems in industrial equipment. The detection of spoilage and allergens is crucial in the food processing process - electrochemical sensors can help automate taste validation, pH reporting, and histamine detection before cooking.
Understand the requirements for electrochemical measurements and sensors
There is a substrate surface material inside the sensor that can serve as a protective layer for the sensing electrode. The main function of this material is to regulate the number of molecules that can enter the electrode surface and filter out any poor particles that may affect the accuracy of the sensor.
The core of a sensor consists of three main parts. The working electrode (WE) is the place where electrochemical reactions occur. When particles collide with the working electrode, oxidation (loss of electrons) and reduction (acquisition of electrons) reactions occur, resulting in electron flow and the generation of current. It is crucial to maintain a constant potential on the working electrode in order to accurately measure the current generated by the redox reaction (Figure 2).
Provide sufficient current to the electrode (CE) to balance the redox reactions occurring on the working electrode (WE), thereby forming complementary pairs. The reference electrode (RE) is used to measure the potential of the working electrode (WE) and provide feedback to establish the voltage across the electrode (CE).
In electrochemical sensors (Figure 3), high edge resistance is an adverse factor that should be minimized as much as possible, which can be achieved by placing the reference electrode (RE) close to the working electrode (WE). The current flowing through the low side resistance represents the output of electrochemical measurement and can be used to derive the output voltage of the sensor
Requirements for sensors
Whether used for consumer, medical, or industrial applications, electrochemical sensors must meet a series of key technical requirements set by designers. The factors of high precision and low noise are self-evident. In addition, electrochemical sensors must also be able to perform simple calibration to meet a wide range of application requirements - as packaging or usage may immediately or over time affect calibration.
In addition, due to the deployment of many electrochemical sensors in portable or low-power solutions, such as wearable medical technology or industrial technology nodes, a series of packaging requirements need to be addressed. Engineers need solutions with low-power operating characteristics to support battery powered applications, and require these solutions to be compact and flexible in size to support multiple sensor configurations and easy system integration. Intelligent preprocessing is also an important feature that many engineers are concerned about, as it can achieve more complex calibration and noise filtering, thereby supporting more accurate data transmission.
Common sensor applications in the field of science
Electrochemical sensors are widely used in life science and medical care, including detecting the alcohol content in blood and realizing continuous glucose monitoring (CGM) - an important part of diabetes management. One in every 11 people in the world suffers from diabetes, a chronic disease [1]. It is expected that the compound annual growth rate (CAGR) of the CGM equipment market will reach 9% between 2023 and 2032.
Onsemi's CEM102 is an advanced miniature analog front-end (AFE) designed for high-precision measurement of electrochemical currents, targeting the latest clinical and portable medical devices. Efficient and flexible operating power consumption: In disabled mode, the power consumption is only 50 nA; 2 uA in sensor bias mode; In active measurement mode with continuous conversion of 18 bit ADC, it is 3.5 uA and supports two battery options: 1.3-1.65 V and 2.375-3.6 V. This means that a market leading 14 day operating time can be achieved with only a 3mAh battery. CEM102 supports 1 to 4 electrodes, and its compact 1.884 x 1.848 mm package makes the product smaller in size and has a longer battery life, making it ideal for IoT applications. The combination of ultra-low power consumption, flexible configuration, and compact size makes it an ideal solution for electrochemical sensor applications.
In addition to medical science, electrochemical sensors are also an ideal choice for detecting toxic gases in industrial applications or measuring pollution and air quality in environmental applications. They utilize the chemical reaction between the target gas and the electrode to generate an electric current proportional to the concentration of a specific gas. The 20mm electrochemical sensor is widely used for measuring various toxic gases, including carbon monoxide, hydrogen sulfide, nitrogen oxides, and sulfur, and supports simple "plug and play" replacement. The applications of these sensors are diverse, ranging from air quality sensors in urban environments to intelligent agricultural applications for monitoring plant growth.
Similarly, electrochemical sensors such as potentiometers or corrosion sensors are also crucial in environments such as laboratories, mining operations, and material production. They serve as important tools for providing feedback and managing hazardous substances in production systems, ensuring operational safety.
In order to improve production yield and efficiency, electrochemical sensors have also been used in food production. Here, handheld portable devices and large automated equipment are used for food quality control to ensure taste and identify spoilage, allergens, or harmful chemicals.
Epilogue
With the continuous development of electronic technology, enterprises need pioneering solutions that not only redefine expectations, but also shorten time to market and increase flexibility, thus providing space for new applications. Ansenmei's CEM102+RSL15 combination solution helps businesses achieve this goal, bringing not only competitive advantages but also opportunities to improve the well-being of others.
From remote healthcare to environmental monitoring and industrial safety, the applications of electrochemical sensors are diverse and have had a significant impact on society. However, its application potential far exceeds the current scope of application. Through production support and collaboration, electrochemical sensors can contribute to advancing research and enhancing cognition in the medical and other fields. With the continuous development of intelligent technology, as well as advances in auxiliary technologies such as artificial intelligence and machine learning, the impact of electrochemical sensors on our lives will continue to increase, giving rise to new innovations and effectively addressing many long-standing global challenges
