On-skin sensors that monitor vital signs can often cause inflammation, but that may be about to change. According to a new study in Nature Nanotechnology, a new approach to this technology using a nanomesh structure could have positive implications for long-term health monitoring.
The new sensors are inflammation-free, are very gas permeable, and they’re thin and lightweight, without the use of any pesky substrates that can contribute to skin discomfort. That means they can be directly laminated onto human skin for longer periods of time.
The sensors’ mesh structure is made of biocompatible polyvinyl alcohol, which enables that gas permeability without blocking sweat glands, and it’s stretchable without causing any additional discomfort, even if it’s affixed for a considerable amount of time. In tests, only one case of inflammation was discovered, and that was due to a patient’s metal allergies.
They’re also versatile. The mesh conductors can attach to irregular skin surfaces -- say, the tip of a person’s finger -- and maintain their functionality even when a person’s natural body movements folds and elongates the skin.
Nanofibres with a diameter of 300 to 500 nm were prepared by electrospinning a PVA solution, and were intertwined to form a mesh-like sheet. When the nanomesh conductors were placed on the skin and sprayed with water, the PVA nanofibers easily dissolved, and the nanomesh conductor attached to the skin.
According to the study, the approach has opened up a new possibility for the integration of electronic devices with skin for continuous, long-term health monitoring.