Skin-Inspired Multifunctional Autonomic-Intrinsic Conductive Self-Healing Hydrogels with Pressure Sensitivity, Stretchability, and 3D Printability

Mohammad Ali Darabi; Ali Khosrozadeh; Rene Mbeleck; Yuqing Liu; Qiang Chang; Junzi Jiang; Jun Cai; Quan Wang; Gaoxing Luo; Malcolm Xing

doi:10.1002/adma.201700533

Skin-Inspired Multifunctional Autonomic-Intrinsic Conductive Self-Healing Hydrogels with Pressure Sensitivity, Stretchability, and 3D Printability

Adv Mater. 2017 Aug;29(31). doi: 10.1002/adma.201700533. Epub 2017 Jun 22.

Authors

Mohammad Ali Darabi^{1

2

3}, Ali Khosrozadeh², Rene Mbeleck², Yuqing Liu², Qiang Chang², Junzi Jiang¹, Jun Cai⁴, Quan Wang⁵, Gaoxing Luo¹, Malcolm Xing^{1

2

3}

Affiliations

¹ Institute of Burn Research; State Key Lab of Trauma Burns and Combined Injury, Southwest Hospital, Third Millitary Medical University, Chongqing, 400038, China.
² Department of Mechanical Engineering, University of Manitoba, Winnipeg, R3T 5V6, Canada.
³ Manitoba Institute for Materials, Winnipeg, Manitoba, R3T 2N2, Canada.
⁴ Department of Electrical and Computer Engineering University of Manitoba, Winnipeg, Manitoba, R3T 5V6, Canada.
⁵ Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong.

PMID: 28640439
DOI: 10.1002/adma.201700533

Abstract

The advent of conductive self-healing (CSH) hydrogels, a class of novel materials mimicking human skin, may change the trajectory of the industrial process because of their potential applications in soft robots, biomimetic prostheses, and health-monitoring systems. Here, the development of a mechanically and electrically self-healing hydrogel based on physically and chemically cross-linked networks is reported. The autonomous intrinsic self-healing of the hydrogel is attained through dynamic ionic interactions between carboxylic groups of poly(acrylic acid) and ferric ions. A covalent cross-linking is used to support the mechanical structure of the hydrogel. Establishing a fair balance between the chemical and physical cross-linking networks together with the conductive nanostructure of polypyrrole networks leads to a double network hydrogel with bulk conductivity, mechanical and electrical self-healing properties (100% mechanical recovery in 2 min), ultrastretchability (1500%), and pressure sensitivity. The practical potential of CSH hydrogels is further revealed by their application in human motion detection and their 3D-printing performance.

Keywords: 3D printing, bodily motion sensors; conductive hydrogels, double network; ionic crosslinking; poly(acrylic acid)-chitosan-polypyrrole, self-healing hydrogels.