A Flexible Dual‐Mode Capacitive Sensor for Highly Sensitive Touchless and Tactile Sensing in Human‐Machine Interactions

Abstract

Human‐machine interaction(HMI) is extensively employed in various applications such as robotic control and augmented reality/virtual reality. However, HMIs are mainly based on single‐interaction mode, requiring bulky equipment to be worn or sustaining physical contact with the interfaces, resulting in limited interaction efficiency and intelligence. Here, it proposes a novel flexible dual‐mode capacitive sensor using 12 sensing units for touchless and tactile sensing during HMIs, the sensor has a labyrinth‐patterned electrode to improve the performance of proximity sensing and a truncated pyramid‐shaped porous hierarchical dielectric structure to improve the pressure sensing performance. The fabricated dual‐mode sensor is characterized by a high proximity detection range of up to 110 mm, the pressure detection range is from 0 to 200 kPa with a sensitivity of 0.464% kPa−1. Further, the dual‐mode sensor exhibits excellent discrimination between proximity and pressure signals, along with remarkable stability and repeatability. Then, a touchless‐tactile HMI platform is developed for real‐time control of robotics through accurate perception of touchless hand gestures and contact‐pressing interactions. This platform demonstrates the superior dual‐mode sensing performance of the sensor and validates its potential in future intelligent HMI scenarios.

Facile Electret-Based Self-Powered Soft Sensor for Noncontact Positioning and Information Translation

“…Furthermore, by integrating the transparent sensors into eyeglasses, we are allowed to detect the small motion of a blink, giving a demonstration of information encoding and translation through the combination of blink and Morse code, which may enable disabled patients, for instance, LIS patients, to communicate. We envision that such electret-based noncontact soft sensors can be further improved to be stretchable and capable of detecting long-distance objects for more powerful applications in the field of human-machine interfaces (HMIs). − …”

Latest developments and trends in electronic skin devices

“…Figures 3C, 4D, 5A, 5B, 6C, 12A, 12C, 13A, 13C a nd 14A are cited from the researches in refs. [62,72,82,83,95,199,200,215,217,224,225] , respectively, showing partial body parts of the participants in the experiment. The purpose of these citations is to present the relevant research results and experimental methods more intuitively.…”

“…Some scholars installed e-skins at the joint positions of hands or gloves and achieved synchronized control of a robotic hand by decoding the characteristic information transmitted by these e-skins in real time [220] . For the latter, the basic strategy is to install e-skins on the surface of the machinery so as to give the machinery tactile ability [221][222][223] [Figure 14A (i) and Figure 14B (i)] [224][225][226][227][228][229] .…”

“…Lu et al developed hydroxypropyl cellulose (HPC)-based eutectic gels with high conductivity, transparency, and anti-freezing properties with 98.1% resilience suitable for wearable applications by introducing HPC into a metal salt-based deep eutectic solvent (MDES) [225] . Self-powered e-skin composed of this Eutectic Gel-Based Triboelectric Nanogenerator (E-TENG) prepared using this eutectic gel possesses excellent performance.…”

“…Luo et al demonstrated a capacitive-dielectric integrated pressure sensor, micro-conformal electrodedielectric integration (MEDI), which has a complex structure of graphene nanowalls (pyramid-shaped top electrode)/PDMS (pyramid-shaped dielectric layer)/ZnO (pyramid-shaped dielectric layer)/poly(methyl [224] , (ii) structure, sensing characteristics and synchronization control of e-skin based on E-TENG [225] , (iii) demonstration of remote control of a robotic arm using the SR/TSH/dispersant/PPMS e-skin [226] ; (B) Schematic diagram of mechanical tactility: (i) concept of mechanical tactile [227] , (ii) demonstration of mechanical haptics of MXene/PU-MXene e-skin [228] , (iii) mechanical haptic signals and its recognition of braille text of MEDI e-skin [229] . E-TENG: Eutectic Gel-Based Triboelectric Nanogenerator; GNWs: graphene nanowalls; PDMS: polydimethylsiloxane; MEDI: micro-conformal electrode-dielectric integration.…”