A CMOS Watchdog Sensor for Certifying the Quality of Various Perishables with a Wider Activation Energy

We developed a CMOS watchdog sensor that simulates the changes in quality of perishables such as farm and marine products. The sensor can imitate a chemical reaction that causes the changes in the quality of perishables, with a wide range of activation energy from 0.1 eV to 0.7 eV. Attached to perishable goods, the sensor simulates the deterioration of the goods caused by surrounding temperatures. By reading the output of the sensor, consumers can determine whether the goods are fresh or not. This sensor consists of subthreshold CMOS circuits with a lowpower consumption of 5 μW or less. key words: CMOS, sensor, subthreshold, translinear, low power, quality guarantee