Figure 15.

(A) A disassembled view of a multilayer stretchable circuit with interconnected microelectronics and flexible islands with soft electrodes on the bottom layer. Additional layers and VIAs can be fabricated. (B) Production of VIAs: (i) The flexible printed circuit board and GaIn interconnects were encapsulated in a stretchable elastomer; (ii) The selected traces and pads were accessed by vertical laser ablation; (iii) When spray coating on a patterned stencil, the cavities were filled with liquid metal; (iv) The patterned stencil was removed before encapsulation of VIAs and new circuit layers. (C) EMG signals from repeated hand gestures were transmitted to a computer application. (D) Fully integrated EMG patch on the forearm (inset: adhesion of the EMG patch to the skin during hand gestures) [102]. Copyright 2019, Royal Society of Chemistry.