Body‐Patchable, Antimicrobial, Encodable TENGs with Ultrathin, Free‐Standing, Translucent Chitosan/Alginate/Silver Nanocomposite Multilayers

Abstract Harvesting sustainable energy opens new avenues for powering portable electronic devices using triboelectric nanogenerators (TENGs). Synthetic metals and polymers are used to construct most of the TENGs. Hence, ultrathin, free‐standing, translucent, and chemically bonded chitosan (CH)‐ and alginate (AL)‐based biopolymeric films are introduced here. These films are fabricated using a low‐cost and environmentally friendly layer‐by‐layer (LbL) self‐assembly method and impregnated with AgNO 3 (S) in the final fabrication step (denoted as [(CH/AL) n :(CHS/AL) 1 ] n+1 ). The LbL‐assembled film displays remarkable antimicrobial and triboelectric properties, demonstrating a new type of TENG that is implantable in the body. By varying the number of CH and AL depositions, the dependence of TENG behaviors on thickness is investigated. It is demonstrated that a 0.87‐µm‐thick [CH/AL] 8 TENG resulted in the highest electrical output performance of 474 V and 36.9 mA m −2 due to the highest surface potential and the lowest work function of 239.4 mV and 4.2 eV, respectively. A free‐standing [(CH/AL) 49 :(CHS/AL) 1 ] 50 TENG is designed for antimicrobial skin‐patchable shape‐adaptive nanogenerators, displaying ultrahigh translucency, long‐term mechanical stability, and exceptional versatility. It is then attached to the arm to detect external stimuli, and the feasibility of its use as an encodable skin‐touch sensor is demonstrated.