Scalable and high-performance pressure sensors for wearable electronics
Flexible pressure sensors and wearable devices incorporating one or more flexible pressure sensors, and methods of making the same. A flexible pressure sensor includes a first layer including a plurality of pressure-sensitive microstructures, and a second layer including one or more electrode pairs, each of the one or more electrode pairs including a first electrode positioned adjacent a second electrode on the second layer. The first and second electrodes may be positioned on the second layer in a side-by-side configuration.
1 . A method of making a flexible pressure sensor, the method comprising:
forming a first layer including a plurality of pressure-sensitive microstructures, wherein the forming the first layer includes:
forming a polymer template having an inverse mesh structure by hot-pressing a screen mesh into a surface of a polymer substrate;
removing the screen mesh from the polymer substrate to form the polymer template having an inverse mesh microstructure;
forming a conductive microstructured film on the polymer template; and
removing the conductive microstructured film from the polymer template, the conductive microstructured film including a conductive material embedded in a silicone material; and
forming a second layer including one or more electrode pairs, each of the one or more electrode pairs comprising a first electrode positioned adjacent a second electrode on the second layer; and
attaching the first layer to the second layer, wherein the first layer includes no electrodes formed thereon in proximity to the one or more electrode pairs of the second layer.
2 . The method of claim 1 , wherein the forming the conductive microstructured film on the polymer template includes applying the conductive material on the polymer template having the inverse mesh microstructure, casting an elastomer precursor material on the polymer template, and curing or drying the elastomer precursor to form the conductive microstructured film.
3 . The method of claim 1 , wherein the conductive material comprises a conductive carbon nanotube (CNT) material, and the silicone material comprises polydimethylsiloxane (PDMS).
4 . The method of claim 1 , wherein the polymer template comprises polystyrene (PS).
5 . The method of claim 1 , wherein the forming the second layer comprises
printing a conductive ink pattern on a flexible polymer substrate to form the one or more electrode pairs on the flexible polymer substrate.
6 . The method of claim 5 , wherein the flexible polymer substrate comprises polyethylene naphthalate (PEN).
7 . The method of claim 5 , wherein the conductive ink comprises a silver ink.
8 . The method of claim 5 , wherein the printing comprises inkjet printing.