Takao Someya Group/University of Tokyo. In a paper published Monday in Nature Nanotechnology, Akihito Miyamoto and colleagues offer an alternative in the form of ultrathin meshes that offer direct integration with the soft surface of the skin. They involve virtually no mechanical footprint while allowing skin to breathe and sweat as normal. Medical uses aside, the new nanomesh technology offers a crucial advance in wearables,
Miyamoto’s nanomesh is hardly the first push into skin-based interfaces. Over the past several years, light-based and biochemical sensors have been laminated onto human skin for a variety of purposes, including skin-based displays and electrical, chemical, and physical sensors. Some implementations are even designed for long-term use, offering, for example, the possibility of persistent brain-machine interfaces via soft, foldable electrodes.
A key limitation of prior efforts has been the necessity of a substrate, a thin base layer that connects electronics to skin. Substrates limit things in several ways, including overall softness, weight, and gas permeability. They just don’t breathe very well.
The nanomesh described in the new paper offers a substrate-free interface. That’s the advance. The mesh here is constructed on a basis of polyvinyl alcohol (PVA), a synthetic water-soluble polymer that’s already used in a variety of medical applications. The result is gas-permeable, doesn’t block sweat glands, and stretchable enough to be worn for long periods without discomfort.
“Touch, temperature and pressure sensors placed on the fingertips are connected by mesh conductors with an e-textile system using a wireless module,” the paper explains.