Patterned Liquid-Metal-Enabled Universal Soft Electronics (PLUS-E) for Deformation Sensing on 3D Curved Surfaces

Liquid metals with metallic conductivity and infinitely deformable properties have tremendous potential in the field of conformal electronics. However, most processing methods of liquid metal electronics require sophisticated apparatus or custom masks, resulting in high processing costs and intricate preparation procedures. This study proposes a simple and rapid preparation method for patterned liquid-metal-enabled universal soft electronics (PLUS-E). The utilization of selective adhesion of the liquid metals on stretchable substrates and the adaptive toner mask enables rapid fabrication (<2 s/100 cm²), excellent stretchability (800% strain), and high forming accuracy (100 μm). Benefiting from the adaptive deformation of the substrate and toner mask, PLUS-E can be conformally applied to any shape of 3D surfaces. Besides, the stability of PLUS-E on 3D surfaces is improved by low-fluidity liquid metal composites. The finite element simulation is used to accurately forecast the deformation and resistance changes of the PLUS-E, and it provides guidance for device design and manufacturing. Finally, this method was utilized to develop various sensors for detecting human motion, catheter bending, and balloon expansion. All of them have obtained stable and reliable signal measurements, demonstrating the usefulness of PLUS-E in real-world applications.