Improved 555 Multivibrator to Measure Degradable Supercapacitive Pressure Sensors

Capacitive pressure sensor has been widely used and developed due to its high sensitivity, fast response and good mechanical robustness. In order to design a degradable supercapacitive pressure sensor, a practical pressure measuring device was developed by using 555 multivibrator and STM32. The sensor adopts supercapacitor structure, uses 555 timer multivibrator circuit as sensor detection circuit, STM32 as precision output control module, which can quickly and accurately convert capacitance signal into frequency signal. In addition, in the low voltage range (< 250 Pa), the sensitivity is 1.63 kPa-1, and the fast response time of 45 ms can be achieved. It has the advantages of small volume, low power consumption and digital signal output.