Where the rubber meets the hand: Unlocking the sensing potential of dielectric elastomers

Abstract

Practice makes perfect to some extent. Research has shown that musicians who practice the piano for long periods of time can suffer a range of hand problems from loss of control to diminished speed. Now imagine a rubber keyboard that is springy, soft, and elastic. This is the new type of input device that dielectric elastomers (DE) can create. However their usage in large sensing systems is limited by a scalability challenge. Each DE sensor is married to a pair of connection cables and electronics, adding to the complexity of the background overheads. A new efficient multi‐frequency method is presented that is capable of detecting internal pressure changes from a difference in the DE's capacitance without the need for any additional wires or connections. This effectively segments the DE into smaller sections, achieving information from a single sensor equivalent to multiple sensors. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 465–472

Capacitive Stretch Sensing for Robotic Skins

“…Hence, C L decreased with increasing frequency. This is consistent with the frequency sweeps published by Xu et al [26][27][28] and Tiggelman et al 22 At 0 mm, the resistance of the top electrode was 350 kO, and the resistance of the bottom electrode was 361 kO. At 15 mm, the static resistances of both electrodes settled at approximately the same values, and at 30 mm, the top and bottom static resistances dropped by 20% and 25%, respectively.…”

“…In a later study, Xu et al utilized the effect of capacitance underestimation for sensing local deformations on a single DE sensor, 27,28 by simultaneously applying sinusoidal excitation signals with different frequencies. Similar to the selfsensing example, 26 the resistivity of the sensor electrodes caused an attenuation of excitation voltages with high frequencies.…”

Electronic Skin Wearable Sensors for Detecting Lumbar–Pelvic Movements

“…The commercially available stretch sensor, StretchSense, is a flexible strain gauge sensor like the E-Skin sensor we used in this study [65]. However, the StretchSense sensor utilizes capacitive strain sensing to measure the degree of strain [66]. Capacitive-based strain gauge sensor has a 5-layered sandwich structure, a dielectric layer sandwiched between two electrode layers and protected by two protective layers [66].…”

“…However, the StretchSense sensor utilizes capacitive strain sensing to measure the degree of strain [66]. Capacitive-based strain gauge sensor has a 5-layered sandwich structure, a dielectric layer sandwiched between two electrode layers and protected by two protective layers [66]. Compared to StretchSense, the E-Skin sensor utilizes piezoresistive strain sensing that consists of a 3-layered structure, in which a stretchable conductive layer is protected by two protective layers (see Figure 1).…”

Self-Healing and Damage Resilience for Soft Robotics: A Review

“…Recently, Cao et al (2017b) demonstrated the use of high-resistive, ionic, self-healing hydrogels as DEA electrodes, showing how work toward improving self-healing ionic hydrogels is also improving damage resilience in soft robotic actuation. Likewise, DEAs have also been used as sensory components in soft electronics (Iskandarani and Karimi, 2012;Xu et al, 2016), so progress made toward fault-tolerant and self-healing DEAs can also be applied to soft sensors and electronics. Looking to the future, LMPAs could potentially be used in place of room-temperature liquid metals in self-healing soft electronics, thereby adding additional structural function, although simultaneously introducing the need for thermal control.…”