Polymer-based printed electrolytic capacitor and its circuitry application in a low pass filtering, rectifying and energy storage unit

Abstract

We report the fabrication of flexible, printed polymer electrolytic capacitors and their implementation in printed electronics applications such as filtering, rectification and energy harvesting and storage. Capacitors were fabricated by depositing conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate onto porous anodized aluminum foil and yielded specific capacitance of 1 µF cm−2. This is far higher than values reported for printed plate capacitors and opens up the possibility of new applications in printed electronics related to filtering and smoothing at low frequencies. In this work, we have used printed polymer electrolytic capacitors to implement a resistor capacitor first order 1.03 kHz passive low pass filter, a full wave bridge rectifier circuit and a piezo-transducer energy harvester. An integrated full wave bridge rectifier based on these devices shows an efficiency of 80.5% at 1 kHz. When integrated with a vibration-motion based flexible piezoelectric transducer, the devices are able to generate and store about 1 mJ energy, which is a sufficient amount of energy for some low power electronics applications.