Stretchable and Conductive Graphite/PDMS Ink for 3D Printing Multi-Sensor Wearable Devices

Electronic skins are complex systems requiring the integration of multiple materials in layered sensor architectures and wiring which is typically achieved with high-end microfabrication tools in a cleanroom environment. This creates an obstacle for the development of inexpensive, disposable, use-at-home and personalised devices for health monitoring. Here, we will present a simple strategy for direct writing (3D printing) of bioelectronic sensors on textile. The sensors are realised using a very limited set of low-cost inks composed only of graphite powders, silicone and a conductive gel. By adapting sensor architectures in 2D+ we were able to produce ElectroMyoGraphy (EMG), strain, and pressure sensors. The sensors are printed directly onto stretchable textile gloves and function as an integrated multimodal monitoring system. Gloves demonstrated functionality by recording simultaneous readings of pinch strength, thumb movement, and EMG of the abductor pollicis brevis muscle. Our approach is targeted towards home tracking of hand function for patients with musculoskeletal and neurological disorders.