Fig. 1: Vertically-separated multilayer stretchable circuit design.
From: Multilayer stretchable electronics with designs enabling a compact lateral form
a Schematics of the Vertically-Separated Multilayer Stretchable Circuit (VSMSC). The islands (red box) are non-deformable regions designated for assembling rigid components. The vertically-separated stretchable interconnectors (black box) are deformable regions to absorb strain more efficiently. b Exploded schematics of the VSMSC with quadruple layers. The rigid interlayers (cyan, SU8) are only formed between the island layers, not between the stretchable interconnector layers. c 3D illustration of the assembled VSMSC. The stretchable interconnectors are vertically separated. The circuit layers are vertically interconnected through via holes in the island. d, e 3D illustration of the vertically separated stretchable interconnectors (d) before stretching and (e) after stretching. f Optical image of the fabricated VSMSC with quadruple layers. g Optical image of cross-sectional side view of the VSMSC. The stretchable multi-layer interconnectors are separated vertically. The separated interconnectors are electrically connected through three different types of VIAs (Dashed boxes: Blind (Magenta), Buried (Green), Through (Orange)) in non-deformable islands. h, i Micrographs of side views of the vertically separated stretchable interconnectors (h) before and (i) after low modulus silicone encapsulation.
