Flexible no-drift data glove using ultrathin silicon for the metaverse

The ideal bending sensors should be able to accurately measure finger movements and maintain consistent sensitivity after repeated use. Existing bending sensors have problems with the time-dependent drift of the sensor output and the sensitivity decreasing over time because of the viscoelasticity of the adhesive and film in the sensors. Here, we present a flexible piezoresistive strain sensor made of ultrathin 5-μm silicon (Si), attached to a 2-μm-thick parylene substrate with Au wiring using water-vapor-plasma-assisted Au–Au direct bonding to eliminate the intrinsic viscoelastic effects of the adhesive and film. The sensor shows no noticeable drift or degradation after 10,000 bending cycles.