SKIN-MOUNTABLE ELECTRONIC DEVICES AND METHODS OF USING AND FABRICATING THE SAME
Skin-mountable electronic devices and methods suitable for fabricating and using the devices. One embodiment of such a device includes a flexible structure comprising a pattern of individual interconnected traces each comprising a portion of an electrically-conductive layer that overlies and directly contacts an underlying portion of an elastomeric layer. At least some of the portions of the electrically-conductive layer within the pattern are functional electrodes of the skin-mountable electronic device.
1 . A method of fabricating a skin-mountable electronic device, the method comprising:
producing a stack comprising a substrate, an intermediate layer that overlies the substrate, an elastomeric layer that overlies the intermediate layer, and a nanowire mesh layer that overlies and directly contacts the elastomeric layer;
patterning and etching the nanowire mesh layer and the elastomeric layer to define a pattern that overlies the intermediate layer, the pattern comprising individual interconnected traces each comprising a portion of the nanowire mesh layer that overlies and directly contacts an underlying portion of the elastomeric layer;
treating the stack to promote debonding of the intermediate layer from the substrate;
mechanically peeling the pattern and the intermediate layer simultaneously from the substrate; and
removing the intermediate layer from the pattern to yield a nanocomposite elastomer structure that is a component of the skin-mountable electronic device, the portions of the nanowire mesh layer within the nanocomposite elastomer structure being functional electrodes of the skin-mountable electronic device.
2 . The method of claim 1 , wherein the producing step comprises forming the nanowire mesh layer of a network of randomly oriented metallic nanowires.
3 . The method of claim 1 , wherein the pattern defined by the patterning and etching step comprises a deformable honeycomb pattern of the individual interconnected traces and connections therebetween.
4 . The method of claim 3 , wherein each of the individual interconnected traces and the connections therebetween are formed to comprise a portion of the elastomeric layer.
5 . The method of claim 4 , wherein at least some and fewer than all of the individual interconnected traces and the connections therebetween are formed as portions of an electrically-conductive layer, the portions of the electrically-conductive layer defining multiple different conductive paths that include at least first and second conductive paths that are not electrically connected to each other within the nanocomposite elastomer structure.
6 . The method of claim 5 , wherein the first conductive path is formed to comprise the portions of the electrically-conductive layer of a first plurality of the individual interconnected traces that are electrically connected to each other in electrical series, and the second conductive path is formed to comprise the portions of the electrically-conductive layer of a second plurality of the individual interconnected traces that are electrically connected to each other in electrical series.
7 . The method of claim 6 , wherein functional electrodes are formed of the portions of the nanowire mesh layer so as to be located within the honeycomb pattern, to comprise at least a first functional electrode that is electrically connected to the first conductive path, and to comprise a second functional electrode that is electrically connected to the second conductive path.