E‐Skin Tactile Sensor Matrix Pixelated by Position‐Registered Conductive Microparticles Creating Pressure‐Sensitive Selectors

Abstract

Electronic skin (E-skin) imitates human skin by converting external stimuli into electrical signals. E-skin requires high flexibility and a high level of device integration. Unlike conventional E-skin creation methods, a highly sensitive pressure sensor matrix (100 pixels cm −2 ) made of position-registered elastic conductive microparticles (MPs) is created. The MPs form a Schottky junction with the bottom electrode and the current through the junction is sensitive to external pressure, forming a simple one-selector two-terminal device array. The Schottky junction eliminates the electrical cross talks between the sensor pixels consisting of 64 MPs in each. The flexible pressure sensor matrix is used as an artificial fingertip for Braille reading and as an electronic scale based on detailed force distribution. This work opens up the possibility that assembled MPs, which have been a long-standing research topic in academia, can be used to make practical electronic devices.

Physical sensors for skin‐inspired electronics

“…Components used in the mechanical sensors can be divided into active materials and supporting materials. Metal‐based materials (eg, liquid metals, metal particles, and NWs), carbon‐based materials (eg, carbon black [CB], CNT, and graphene), conductive polymers (eg, PPy, poly(3,4‐ethylene dioxythiophene):poly(styrene sulfonate) [PEDOT:PSS], and hydrogel), and other materials (eg, MOF, MXene) have been used as the active materials.…”

“…Copyright 2018, Tsinghua University Press and Springer‐Verlag GmbH Germany. C, Conductive polymers (PEDOT:PSS) . Copyright 2018, Wiley‐VCH.…”

Artificial Perception Built on Memristive System: Visual, Auditory, and Tactile Sensations

“…b) Schematic description of the Schottky junction tactile sensor and relative forward current increase of the sensor measured at 5 V under different external pressures. Reproduced with permission . Copyright 2018, John Wiley and Sons.…”

“…Reproduced with permission. [81] Copyright 2018, John Wiley and Sons. c) Photograph of the active matrix (12 Â 12 pixels) integrated with a large-area (9 Â 9 cm 2 ) pressure-sensor nanofiber sheet, and pressure versus resistance curve of the nanofiber sensor (red) and thin-film sensor (black) sandwiched between Au electrodes.…”

“…[88,89] Recently, a pressure sensor matrix (100 pixels cm À2 ) made of position-registered elastic conductive microparticles was demonstrated with high sensitivity, good mechanical property, and high spatial resolution. [81] As shown in Figure 7b, the microparticles form a Schottky junction with the bottom electrode, where the contact area is changeable under pressure. It is worth mentioning that the formation of the Schottky junction successfully eliminates the electrical crosstalk and leakage current in the large sensor array, making it more practical compared to earlier reported structures.…”