E-Skin Development and Prototyping via Soft Tooling and Composites with Silicone Rubber and Carbon Nanotubes

Abstract

The strategy of embedding conductive materials on polymeric matrices has produced functional and wearable artificial electronic skin prototypes capable of transduction signals, such as pressure, force, humidity, or temperature. However, these prototypes are expensive and cover small areas. This study proposes a more affordable manufacturing strategy for manufacturing conductive layers with 6 × 6 matrix micropatterns of RTV-2 silicone rubber and Single-Walled Carbon Nanotubes (SWCNT). A novel mold with two cavities and two different micropatterns was designed and tested as a proof-of-concept using Low-Force Stereolithography-based additive manufacturing (AM). The effect SWCNT concentrations (3 wt.%, 4 wt.%, and 5 wt.%) on the mechanical properties were characterized by quasi-static axial deformation tests, which allowed them to stretch up to ~160%. The elastomeric soft material’s hysteresis energy (Mullin’s effect) was fitted using the Ogden–Roxburgh model and the Nelder–Mead algorithm. The assessment showed that the resulting multilayer material exhibits high flexibility and high conductivity (surface resistivity ~7.97 × 104 Ω/sq) and that robust soft tooling can be used for other devices.

Wide Range Strain Distributions on the Electrode for Highly Sensitive Flexible Tactile Sensor with Low Hysteresis

“…As the pressure increased, the contact area between the MADH and the interdigital electrodes increased, causing a decline in contact resistance. Moreover, owing to deformation of the MADH film caused by the pressure, the distance between the conductive agents within the SWCNT/PDMS conductive film is reduced to quantum size (tunnelling effect) , or contact (percolation effect). − As a result, the sensor is able to form more conductive pathways (Figures b and S10). Accordingly, under the synactic effects (Figures S10 and S14, SI) of the contact area change rate, percolation effect, and tunneling effect, the current of the MADH sensor increased with increasing pressure.…”

Bioinspired skin towards next-generation rehabilitation medicine

“…MoS 2 、Silicon wafer、PDMS、3D porous graphene, Tattoo-base paper, Silicon/SU8, Single-walled carbon nanotube, PET film, Gold nanowires (García-Ávila et al, 2021;Wei et al, 2021;Cao and Cai, 2022; Frontiers in Bioengineering and Biotechnology frontiersin.org sensors which allow people with disabilities to touch the world with the help of haptic sensors (Park et al, 2018). Researchers at RMIT University in Australia (Rahman et al, 2020) have developed a new electronic skin by combining three technologies previously pioneered and patented by the team: stretchable electronics, self-modifying coatings, and electronic memory cells.…”

Self‐Healing, Reconfigurable, Thermal‐Switching, Transformative Electronics for Health Monitoring

“…The unique mechanical and electrical properties of the advent of flexible electronic devices allow their use in soft robots, [1,2] flexible sensors, [3,4] and flexible printed circuit boards (PCBs). [5,6] In particular, the skin-interfaced soft wearable electronics can monitor vital physiological data for early disease diagnostics, [7,8] effective in-time treatment, [9,10] and humancomputer interfaces, [11,12] as well as provide electronic skin [13,14] to detect heat stress. However, these soft and flexible devices are inevitably susceptible to mechanical damage and failure from external friction, torsion, tear, and compression, presenting challenges for their long-term use in harsh environments.…”