Figure 1: Fabrication of the porous electrode with steam etching.
From: Solderable and electroplatable flexible electronic circuit on a porous stretchable elastomer
(a) Process for fabricating a porous PDMS substrate using steam etching and metal (Au and Ti) deposition. (b) Schematic diagram showing the steam etching process. (c) A side-view of SEM image of a porous PDMS film. (d) Top view of SEM image of a porous PDMS film, and an inset showing a wide porous area. (e) Au- and Ti-deposited porous PDMS thin films (thickness: Ti (500 Å), Au (2,000 Å)) and the winding of the film around a finger, maintaining close contact with the skin. (f) Schematic diagram showing the initial electrical connections and (g) an SEM image of a metal-deposited porous layer before. (f) Schematic diagram showing the mechanism by which the structure stretched without incurring electrical disconnections (blue arrows: strain direction). (h) After 20,000 stretching cycles under 30% strain. (The white arrowheads indicate breaks in the structure after 20,000 stretching cycles under a 30% strain, whereas white resistor symbols indicate intact conductive paths.) Scale bar, 20 μm (c,d,g and h) and 200 μm (d, inset).
