Direct Fabrication of Stretchable Electronics on a Programmable Stiffness Substrate With 100% Strain Isolation

In this work, an effective method is proposed to enable spatial modulation of the stiffness of elastic substrate through selectively controlling the formation of cross-linked interpenetrating network (IPN). The IPN structure is locally growing on the monomer-injected elastomer through selective ultraviolet light exposure, and the Young’s modulus of selected regions can be significantly enhanced by an order of magnitude. Further experiments and finite element analysis results demonstrate that the selective region exhibits 100% strain isolation characteristic. Finally, a metal oxide thin film transistor (MOTFT) array is integrated on the substrates exhibiting negligible performance variation under 100 % tensile strain and 500 tensile cycling. Our strategy opens up a promising way for fabrication of stretchable substrate.