Robotic Hands with Intrinsic Tactile Sensing via 3D Printed Soft Pressure Sensors

Abstract

Herein, the development of complex 3D intelligent structures such as robotic hands using innovative designs and multimaterial additive manufacturing technology is presented. The distal phalanges of the 3D printed hand presented herein have inherent soft capacitive touch or pressure sensors and embedded electronics. Materials such as thermoplastic polyurethane (TPU), silver paint, conductive polylactic acid composite, graphite ink, etc. are explored to develop five different variants of the sensors using a modified 3D printer, which is capable of extruding conductive ink, metal paste, and polymers. The best‐performing 3D printed soft capacitive touch sensors, formed with silver paint and soft rubber (Ecoflex 00‐30), are integrated on the distal phalanges of the 3D printed robotic hand. These sensors exhibit a stable response with sensitivity of 0.00348 kPa−1 for pressure <10 kPa and 0.00134 kPa−1 for higher pressure. To demonstrate the practical applicability, the 3D printed hand with embedded soft capacitive touch sensors is used for interacting with everyday objects. The tightly integrated sensing elements within the 3D printed structures, as presented herein, can pave the way for a new generation of truly smart material systems that can possibly change their appearance and shape autonomously.

3D Printed Robotic Hand with Embedded Touch Sensors

“…1). This paper extends other works related to this area where only one sensor with the readout circuit is embedded inside the fingertip [14]. The developed sensorised fingertips are robust, show stable response and are affordable.…”

“…The developed sensorised fingertips are robust, show stable response and are affordable. Compared to other works where embedded off-the-shelf sensors have been reported [14,[18][19][20][21], the fingertip presented here have intrinsic sensors realised by fully 3D printing. The presented facile approach has the potential to be scaled up to large-area manufacturing.…”

“…Likewise, wearable systems and tattoo-like eSkins have benefited the field of health monitoring [12,13]. However, most of these conformable eSkins come with the challenge of wear and tear during frequent use [14]. The routing of large amount of wires connecting the sensors and the readout electronics is another challenge, especially in highly dense areas with limited space, of e-skins [8,9,[15][16][17].…”

High-performance printed electronics based on inorganic semiconducting nano to chip scale structures

“…Moreover, as mentioned previously, CP and TP can complement each other in layerby-layer printing of NWs forming vertical 3D stacking. The advances in multi-material additive manufacturing could offer new avenues for introducing eSkin like features in prosthesis and robotics [59,217,218]. For instance, such 3D manufacturing processes could be employed to develop prosthesis with directly integrated or embedded touch sensors, thereby enabling robust limbs that are also free from wear and tear issues.…”

Comparison of Laser-Synthetized Nanographene-Based Electrodes for Flexible Supercapacitors

“…Flexible electronics are expected to bring out a revolution in diverse fields of technology, such as electronic skin [1,2], robotics [3,4] or health-monitoring devices [5][6][7], among others. Most of the recent advances in this context have been possible due to the emergence of new conductive and flexible materials, many of which have reported outstanding results in terms of electrical conduction and integration, such as the polycrystalline silicon (poly-Si) [8,9] or several semiconducting metal 2 of 14 oxides (e.g., SnO 2 , TiO 2 , ZnO or ITO) [10][11][12].…”