Materials
A dielectric film made of polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT) was purchased from Earth Friendly (“[Biodegradable 100%] Wrap returned to soil”). Gelatin powder (17009-01) and glycerol (17029- 00) were purchased from Kanto Chemical. Sodium chloride (NaCl) was purchased from Tomita Pharmaceutical (7647-14-5). Corn starch powder and soybean oil were purchased from a supplier.