Highly Sensitive and Multimodal All-Carbon Skin Sensors Capable of Simultaneously Detecting Tactile and Biological Stimuli

Significance Statement

Recently, design of a stretchable artificial skin with heterogeneous multi-stimuli responses as well as high sensitivity is strongly desired to emulate human skin. In particular, the effective incorporation of chemical or biological detection with tactile sensing in a single device is a challenging task for implementing an artificial skin platform beyond human skin, whereas this has not hitherto been explored in a precise and cost-effective manner. Thus, in response to the ongoing challenges for skin sensors, a rational design of sensing materials and device architecture is strongly required. In this work, we describe the highly sensitive, wearable, and multi-stimuli responsive “all-carbon” skin sensors based on hierarchically engineered elastic carbon nanotube fabrics (i.e. carbon nanotube microyarn), which is capable of detecting heterogeneous external subtle stimuli in a single pixel. In particular, effective multimodal output electric signals can be manipulated as a change of resistance or capacitance under mechanical deformations (including pressure and flexion), touch, temperature, humidity variation, which physiologically enables the communication of feelings and emotions through skin-to-skin contact similar to that of human skin. Moreover, each pixel in our sensor skin can detect and even discern input signals derived from versatile chemical fluids with different dipole moments or pH. This implies the implementation of artificial all-carbon skin sensors incorporated with an electronic nose or tongue beyond the multimodality of human skin as a new platform. We believe that a stretchable, artificial all-carbon skin suggested by us will be an effective way to implement human-interactive smart robots capable of recognizing the robot-human-environment interface and to enable in-situ human monitoring capable of effectively detecting some biological markers as well as tactile stimuli.


Figure Legend

 Multimodal all-carbon skin sensors capable of detecting tactile and biological stimuli (a) Photograph and schematic view of artificial sensor skin using hierarchically engineered carbon nanotube microyarn. (b) Schematic picture representing multimodal sensing of all-carbon skin sensor (c) In-situ change of capacitance in the device in terms of human motion including touching, pressing and flexing. (d) Real-time capacitance measurement in terms of drop volume for two test solvents (water and dodecane).

Highly Sensitive Multimodal All-Carbon Skin Sensors. Global Medical Discovery

Journal Reference

Adv Mater. 2015;27(28):4178-85.

Kim SY1, Park S1, Park HW1, Park do H1, Jeong Y1, Kim do H1.

Department of Organic Materials and Fiber Engineering, Soongsil University, Seoul, 156-743, Korea.


A highly sensitive, wearable, and multimodal skin sensor that uses hierarchically engineered elastic carbon nanotube microyarns is described. Piezocapacitive all-carbon skin sensors simultaneously detect heterogeneous external subtle stimuli, including mechanical deformation, touch, temperature or humidity gradients, and even biological variables with different dipole moments, which enables in situ human monitoring as well as recognition of robot-human-environmental interface.

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About the author

Do Hwan Kim is an assistant professor of Department of Organic Materials and Fiber Engineering at Soongsil University in Korea. He graduated from Hanyang University in 2000 with a bachelor’s degree in Chemical Engineering. He received a Ph.D. degree from POSTECH in Chemical Engineering in 2005 under the supervision of Prof. Kilwon Cho. He was a senior researcher at Samsung Advanced Institute of Technology (2006-2010) and a postdoctoral researcher at Stanford University (2011-2012) and then joined the faculty at Soongsil University from 2012. His research interests include artificial soft sensors to emulate five senses of human (e-skin, e-nose, e-tongue and e-eye), stretchable materials/devices, textronics and energy harvesting system for frontier soft electronics.