Synthesis of a Photo‐Crosslinkable Elastomer for Stretchable Electronics and Its Use in Strain‐Insensitive Pressure Sensors

Abstract A stretchable electronic substrate with strategically positioned rigid and soft islands offers a significant platform to overcome the limitations of current stretchable substrates. This design facilitates the integration of conventional rigid electroactive materials into high‐performance stretchable electronics. This study introduces a photo‐crosslinkable, transparent elastomer substrate based on acrylates. When exposed to UV irradiation, it undergoes selective crosslinking (with crosslinking density and modulus depending on the number of crosslinkers); it can achieve a modulus increase of up to 38 000%. Rigid regions of specific shapes and sizes can be created using a photomask, while soft regions remain intact for expansion during stretching. The substrate is used to produce a capacitive strain/strain‐insensitive pressure (SIP) sensor in which rigid islands act as the dielectric layer of the capacitor; sensitivity to external stimuli is modulated by the modulus of the rigid islands. In addition, a high‐efficiency SIP sensor (SIPS) employing an electrospun dielectric layer, which amplifies the pressure sensitivity by 780‐fold, is developed, ensuring a constant low strain sensitivity.