CPC G01L 1/146 (2013.01) [G01L 1/144 (2013.01); H05K 3/02 (2013.01); H05K 3/4673 (2013.01)] | 20 Claims |
1. A method of producing a flexible structure that comprises a plurality of thin-film layers of elastomeric material and at least one layer of micro-wrinkled electrically conductive material, the method comprising:
a) applying a selective anti-adhesion treatment process to a carrier substrate whereby an outer peripheral region of the substrate provides a strong adhesion region and the area of the substrate within the outer peripheral region provides an anti-adhesion central region;
b) forming, on the carrier substrate, a first plurality of successive thin-film layers of PDMS, each of the successive thin-film layers of PDMS having a smaller ratio of crosslinking agent to base material and hence a higher Young's modulus than a preceding one of the thin-film layer of PDMS;
c) forming, on the last-formed thin-film layer of PDMS, a first thin-film layer of Parylene;
d) placing the carrier substrate in an organic solvent for a first period of time to induce swelling in the first plurality of thin-film layers of PDMS;
e) forming, on the first thin-film layer of Parylene a first further thin-film layer of PDMS;
f) forming by vacuum deposition, on the first further thin-film layer of PDMS, a second thin-film layer of Parylene in which a permanent micro-scale wrinkled surface morphology is generated as a consequence of diffusion of the organic solvent from the first plurality of thin-film layers of PDMS during said vacuum deposition, thus providing a first micro-scale wrinkled Parylene layer;
g) forming and patterning a first layer of electrically conductive material on the first micro-scale wrinkled Parylene layer such that the first patterned electrically conductive material has a micro-scale wrinkled surface morphology conforming to that of the first micro-scale wrinkled Parylene layer, thus providing a first micro-scale wrinkled electrically conductive pattern layer.
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