Mussel‐Inspired Flexible, Wearable, and Self‐Adhesive Conductive Hydrogels for Strain Sensors

• Published in: Macromolecular rapid communications. Vol. 41; no. 2; pp. e1900450 - n/a
• Main Authors: Lv, Rui, Bei, Zhongwu, Huang, Yuan, Chen, Yangwei, Zheng, Zhiqiang, You, Qingliang, Zhu, Chao, Cao, Yiping
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2020
• Subjects: Acrylic Resins - chemistry; Adhesive strength; Adhesives; Adhesives - chemistry; Animals; Automation; Biosensing Techniques; Bivalvia - chemistry; Borates - chemistry; Borax; Conductivity; Conductors; Dopamine; Dopamine - chemistry; Elasticity; Electric Conductivity; flexible; Human motion; Humans; Hyaluronic acid; Hyaluronic Acid - chemistry; Hydrogels; Hydrogels - chemistry; Ions - chemistry; Manufacturing engineering; Mollusks; Motion; Polyacrylamide; Robotics; Room temperature; self‐adhesive; Shear Strength; strain sensors; Stretchability; wearable devices; Wearable Electronic Devices; Wearable technology; self-adhesive; wearable devices; hydrogels; strain sensors; flexible
• ISSN: 1022-1336; 1521-3927; 1521-3927
• DOI: 10.1002/marc.201900450

The latest generation of wearable devices features materials that are flexible, conductive, and stretchable, thus meeting the requirements of stability and reliability. However, the metal conductors that are currently used in various equipments cannot achieve these high performance expectations. Hence, a mussel‐inspired conductive hydrogel (HAC–B–PAM) is prepared with a facile approach by employing polyacrylamide (PAM), dopamine‐functionalized hyaluronic acid (HAC), borax as a dynamic cross‐linker agent, and Li+ and Na+ as conductive ions. HAC–B–PAM hydrogels demonstrate an excellent stretchability (up to 2800%), high tensile toughness (42.4 kPa), self‐adhesive properties (adhesion strength to porcine skin of 49.6 kPa), and good self‐healing properties without any stimuli at room temperature. Furthermore, the fabricated hydrogel‐based strain sensor is sensitive to deformation and can detect human body motion. Multifunctional hydrogels can be assembled into flexible wearable devices with potential applications in the field of electronic skin and soft robotics. Inspired by the adhesion of natural mussels, the synthesized hydrogel exhibits self‐adhesion (adhesion strength to porcine skin of is up to 49.6 kPa), good self‐healing (within 1 h), and high strain sensitivity. It meets the flexibility and stability requirements of the latest generation of wearable devices to detect human body movements.