A sustainable biomass-based electret for face mask and non-volatile transistor memory

An electret filter on the middle layer of disposable medical face masks has a similar function to the charge storage layer on the transistor memory devices. Both applications require a polymer electret to trap charges so that it could establish electrostatic attraction to effectively enhance the filtration efficiency of face mask or modulate the electrical behaviours of transistor memory. By virtue of that very same function, we demonstrate the charge storage performance and memory characteristics of transistor memory using the electret filters of face mask material, from the non-renewable polypropylene (PP) to the biomass-based polymers. We demonstrate dextrin, a biomass-derivative, as a sustainable alternative electret. Due to dextrin being produced natural starch products, it is a renewable material that is biocompatible and eco-friendly. Furthermore, by adding sodium methylsiliconate (SMS), the hydrophobic blended dextrin-SMS transistor memory can maintain inherent prolonged electrostatic charges for over 100 days along with relatively wide memory window of 39.5 V. Ultimately, the non-woven nanofiber electret filter using dextrin-SMS can be successfully produced using an industrial compatible electrospinning technique combined with the addition of polyethylene oxide (PEO) to improve the electrospinability of the mat filter and potentially utilized for future biodegradable face masks and green electronics.