Stretchable Skin‐Like Cooling/Heating Device for Reconstruction of Artificial Thermal Sensation in Virtual Reality

Abstract

Along with visual and tactile sensations, thermal sensation by temperature feeling on the skin can provide rich physical information on the environment and objects. With a simple touch of objects, relative temperature can be sensed and even objects can be differentiated with different thermal properties without any visual cue. Thus, artificially reproducing accurate/controllable thermal sensation haptic signals on human epidermis will certainly be a major research area to reconstruct a more realistic virtual reality (VR) environment. In this study, for the first time, a skin‐like, highly soft and stretchable and bi‐functional (both cold and hot sensation) thermo‐haptic device is reported for wearable VR applications with a single device structure (not separate heater and cooler). The skin‐like thermo‐haptic (STH) device can actively cool down and heat up deformable skin surfaces with instantaneous and accurate adjustment of temperature based upon a feedback control algorithm to mimic desirable thermal sensation with 230% stretchability. As a proof‐of‐concept, the STH device is integrated with a finger‐motion tracking glove to provide artificial thermal sensation information to the skin in various situations such as touching cold beer bottles and hot coffee cups in virtual space. This new type of STH device can offer potential implications for next‐generation haptic devices to provide unique thermal information for a more realistic virtual‐world field and medical thermal treatment.

Recent advances in liquid-metal-based wearable electronics and materials

“…Because most elastic materials for wearables show low thermal conductivity while rigid metals exhibit orders of magnitude higher, there has been a huge trade-off in thermal and mechanical properties in wearable electronic materials ( Lee et al., 2020b ; Zhan et al., 2018 ). Bartlett et al.…”

“…This system is so called, “haptics,” that realizes tactile sensing and tracking motion activity. This stand-alone platform enables a contact-free technology in a virtual world where gaming, training, and entertaining by himself/herself is possible in a forthcoming area ( Kim et al., 2020a , 2020b ; Lee et al., 2020a , 2020b ; Mishra et al., 2020 ; Park et al., 2020 ). Oh et al.…”

Smart Stretchable Electronics for Advanced Human–Machine Interface

“…[15][16][17][18][19] M2H devices provide electrical, thermal, visual, or mechanical feedbacks that simulate various sensations. [20][21][22] H2M control systems use sensors with various mechanisms. These include strain sensors that directly measure deformations due to human motions or stretchable electrodes, which indirectly measure electric signals of the muscle.…”

“…[ 15–19 ] M2H devices provide electrical, thermal, visual, or mechanical feedbacks that simulate various sensations. [ 20–22 ]…”

A General Grid-Less Design Method for Location and Pressure Sensors with High Precision

“…As one of the representative flexible sensor systems, bionic electronic skin has wide applications in medical rehabilitation [ 1 , 2 , 3 ], motion imaging [ 4 , 5 , 6 ], virtual reality [ 7 ], Internet of Things [ 8 ], and other fields. One important feature of electronic skin for pressure sensing is the accurate mapping of both the magnitude and location of the pressure.…”