3D Printed Electronic Skin for Strain, Pressure and Temperature Sensing

Abstract

Electronic skin (E‐skin) that can mimic the flexibility and stretchability of human skin with sensing capabilities, holds transformative potential in robotics, wearable technology, and healthcare. However, developing E‐skin poses significant challenges such as creating durable materials with skin‐like flexibility, integrating biosensing abilities, and using advanced fabrication techniques for wearable or implantable applications. To overcome these hurdles, a 3D‐printed electronic skin utilizing a novel class of nanoengineered hydrogels with tunable electronic and thermal biosensing capabilities is fabricated. This methodology takes advantage of the shear–thinning behavior in hydrogel precursors, allowing to construct intricate 2D and 3D electronic structures. The elasticity of skin using triple crosslinking in a robust fungal exopolysaccharide, and pullulan is simulated, while defect‐rich 2D molybdenum disulfide (MoS2) nanoassemblies ensure high electrical conductivity. The addition of polydopamine nanoparticles enhances adhesion to wet tissue. The hydrogel exhibits outstanding flexibility, stretchability, adhesion, moldability, and electrical conductivity. A distinctive feature of this technology is the precise detection of dynamic changes in strain, pressure, and temperature. As a human motion tracker, phonatory‐recognition platform, flexible touchpad, and thermometer, this technology represents a breakthrough in flexible wearable skins and holds transformative potential for the future of robotics and human‐machine interfaces.

Three-Dimensional Printing of Hydrogels for Flexible Sensors: A Review

“…However, producing robust materials that are flexible like skin, including biosensing capabilities, and employing cutting-edge fabrication methods for wearable or implantable applications are only a few of the major obstacles in the development of E-skin. Roy et al developed a 3D-printed elastomeric hydrogel via triple crosslinking involving defect-driven gelation, Michael addition, and ionic crosslinking [ 95 ]. The crosslinked hydrogel was linked to the circuit and demonstrated successful light-emitting diode (LED) bulb lighting ( Figure 6 a), indicating the potential usage of the hydrogel in making 3D-printed electronic skin.…”

“…Vibrations recorded from the two different acts ( d ). Reproduced with permission [ 95 ]. Copyright © 2024 Wiley-VCH GmbH.…”

Latest developments and trends in electronic skin devices

“…Second, resembling human skin, e-skins need to be carefully designed to provide various sensing capabilities. Examples include the ability to sense stimuli such as strain [13][14][15] , temperature [16,17] , and humidity [18][19][20][21] .…”

Rational Design of Oil-Resistant and Electrically Conductive Fluorosilicone Rubber Foam Nanocomposites for Sensitive Detectability in Complex Solvent Environments

“…Flexible and sensitive sensors have gained significant attention for their development in multifaceted detections, including human motion monitoring, − speech recognition, , temperature sensing, , portable healthcare monitors, − etc. Tremendous advances in these smart sensors have been prompted by urgent applications in various complex and harsh environments, such as extreme humidity/temperature, − electromagnetic interference, and underwater. − However, there are few reports on smart sensors that can be implemented in oil or solvent environments, which should be critically addressed with the increasing demands of application environments.…”