Thermal shape morphing of membrane-type electronics based on plastic-elastomer frameworks for 3D electronics with various Gaussian curvatures

This study demonstrates a means of shape morphing planar membrane-type electronic devices into three-dimensional (3D) structures with various Gaussian curvatures using a plastic-elastomer supportive framework consisting of acrylonitrile-butadienestyrene (ABS) lines with tensile stress inside an Ecoflex film. The plastic part, created by extrusion shear printing (ESP), provides the driving force for shape mor-phing upon thermal annealing, whereas the elastomer part provides a base to mount membrane-type electronic devices and allows a comparably large degree of deformation. To ensure reliable interfacial adhesion in the plastic-elastomer framework, the ABS lines are treated with an allyl-terminated self-assembled monolayer (SAM) for chemical bonding to the Ecoflex layer. To determine control parameters for reliable shape morphing, the annealing conditions (e.g., temperature and time), the printing condi-tions (e.g., shear rate and pitch), and relative thicknesses of the ABS/Ecoflex are examined. Based on these findings, various 3D structures, including bent, cone, saddle, and dome shapes, can be generated from planar forms using ABS-Ecoflex frameworks, which are also predicted by a mechanical finite element method (FEM) simulation. Furthermore, a metal electrode and a membrane-type indium gallium zinc oxide (IGZO) transistor array are successfully mounted on ABS-Ecoflex frameworks and transformed into curvilinear structures without electrical failure.& COPY; 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).