Ecofriendly Transfer Printing for Biodegradable Electronics Using Adhesion Controllable Self‐Assembled Monolayers

Abstract

The biodegradable electronics are on the rise, not just due to their role in medical implants, but also because of their eco‐friendly attributes. A variety of methods, including transfer printing, have been employed to integrate inorganic electronics onto biodegradable polymer substrates. However, the use of expensive materials, multiple intermediary steps, and labor‐intensive procedures can undermine their environment‐friendly benefits. Here, a straightforward yet efficient fabrication method is introduced for creating high‐performance biodegradable electronic devices. This method leverages the controlled adhesion between the biodegradable device and substrate using self‐assembled monolayers of octadecyltrichlorosilane. Mechanical and thermal analyses based on scratch tests and time‐domain thermoreflectance quantify the adhesion by adjusting the packing density of octadecyltrichlorosilane. Controlled adhesion allows the photolithography process without delamination while facilitating easy delamination during transfer printing. The authors demonstrate the direct fabrication of electronics consisted of inorganic materials (Mg, Zn, SiO2, Si nanomembrane) on wafers and transfer‐printing onto polymer substrates via a single transfer step. This streamlined approach enables wafer‐scale fabrication of biodegradable electronics, highlighting its potential for mass manufacturing. Pilot conceptual demonstration of mass‐produced edible hydration sensors and their application in salivation measurement through in vivo model show the potential capability of proposed fabrication method in the use of practical level.