Figure 7.

Multimodal, multifunctional tactile sensor arrays based on FETs. (a) Schematic layouts of the pressure-sensor array integrated with ZnS:Cu phosphor particles. (b) Green, blue, and red color interactive e-skins are used to spatially map and display the pressure applied with C-(left), A-(center) and L-(right) shaped PDMS slabs, respectively. (c) Skin-inspired highly stretchable and conformable matrix networks; a schematic illustration of stretchable and conformable matrix networks (SCMNs) conforming to the surface of a human arm and an expanded network (expansion: 200%) conforming to the surface of a human abdomen (right); the tree branch-like connections of neurons (left bottom); the sensory receptors of the glabrous skin (left top). (d) Schematic illustrations without stimulus and under three different mechanical stimuli for pressure, shear force, and torsion. There were possible geometric deformations of the pyramid-plug structure with mechanical loadings. (e) Schematic of a stress-direction-sensitive electronic skin for the detection and differentiation of various mechanical stimuli including normal, shear, stretching, bending, and twisting forces. (f) A commercial temporary transfer tattoo provides an alternative to polyester/polyvinyl alcohol (PVA) for the substrate; in this case, the system includes an adhesive to improve bonding to the skin. Images are of the back side of a tattoo (far left), electronics integrated onto this surface (middle left), and attached to the skin with electronics facing down in undeformed (middle right) and compressed (far right) states. (a) Reproduced with permission [15]. Copyright 2020, Nano Letters. (b) Reproduced with permission [64]. Copyright 2013, Nature Materials. (c) Reproduced with permission [99]. Copyright 2018, Nature Communications. (d) Reproduced with permission [101]. Copyright 2019, Advanced Materials Technologies. (e) Reproduced with permission [102]. Copyright 2014, ACS Nano. (f) Reproduced with permission [103]. Copyright 2011, Science.