Self-Powered, Hybrid Triboelectric-Piezoresistive Tactile Sensor array-based Artificial Skin for Soft Robots

• Applicants: Dr. Amit Das; Professor Dr. Andreas Fery
• Subject Area: Polymer Materials ; Synthesis and Properties of Functional Materials
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 404941515

The first round of the SPP2100 proposal entitled, “Ultrasoft Long-Range Strain and Self-Powered Touch sensors for Soft Robotic Segments” was focused on developing multifunctional crosslinked rubber-based inexpensive solutions for piezoresistive and triboelectric tactile sensing prototypes and subsequent integration into soft robotic components. In the second phase, we aim to move further ahead with the results extracted from the first phase. The ultrasensitive triboelectric tactile sensor is shown to perceive of a mild touch and this can be further manipulated by additional topographical functionalization. We propose to develop and design functional, commercial rubber substrates by incorporating chemical engineering on the surface, additive manufacturing methods, self-healable properties and transfer-printing of the elastomer for highly sensitive triboelectric and piezoresistive sensing solutions. For the soft robotic applications, piezoresistive sensors with high repeatability and reproducibility are particularly considered. Herein, for the first time, we propose to achieve desired performance with excellent sensitivity by incorporating vacuum-metal layer deposited stretchable interconnector-based strain sensors. Furthermore, instead of single sensor, we aim to fabricate hybrid tactile sensing array-based artificial skins that are ultrastretchable, durable and multi-stimuli responsive with high spatiotemporal resolution. The proposed skin-mimicking tactile module can offer high reproducibility with larger surface coverage on soft robots and record complex tactile information by producing varied electrical voltage signal as a function of vibration, touch or force. Furthermore, the embedded e-skin can also exhibit self-powered characteristic as triboelectric tactile module is expected to produce output current (in microamps) upon contact friction that would be sufficient for running small intensity sensors and arrays. In addition, our objective will also be to integrate self-healing functionality to rubber-based touch and force sensors for long term, all-weather operability and longevity. Finally, current proposal will strongly encourage cumulative development and multilateral research outcome in terms of complex data processing that will be analyzed by collaborative developments of neural network-based machine learning algorithms and computational modelling studies offered by fellow SPP2100 co-contributors. The present proposal involving the development of artificial skin for soft robotic components and signal processing by computational methods, therefore, emphasize particularly on strong collaborative outcomes within the SPP2100 framework in terms of interdisciplinary overlap between e-skin, soft robotics and machine learning.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2100: Soft Material Robotic Systems