Tissue‐Mimetic Supramolecular Polymer Networks for Bioelectronics

• Published in: Advanced materials (Weinheim) Vol. 35; no. 1; pp. e2207634 - n/a
• Main Authors: O'Neill, Stephen J.K., Huang, Zehuan, Ahmed, Mohammed H., Boys, Alexander J., Velasco‐Bosom, Santiago, Li, Jiaxuan, Owens, Róisín M., McCune, Jade A., Malliaras, George G., Scherman, Oren A.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-01-2023
• Subjects: Affinity; Biocompatibility; bioelectronics; Chemical synthesis; Conducting polymers; Elastic Modulus; Electric Conductivity; Electronic materials; Electronics; host–guest chemistry; Humans; hydrogels; Hydrogels - chemistry; Ion currents; Materials science; Mechanical properties; Modulus of elasticity; Moisture content; Networks; Polymers; Polymers - chemistry; Signal monitoring; Stretchability; Supramolecular compounds; supramolecular networks; Supramolecular polymers; Tissues; hydrogels; conducting polymers; host-guest chemistry; bioelectronics; supramolecular networks
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202207634

Addressing the mechanical mismatch between biological tissue and traditional electronic materials remains a major challenge in bioelectronics. While rigidity of such materials limits biocompatibility, supramolecular polymer networks can harmoniously interface with biological tissues as they are soft, wet, and stretchable. Here, an electrically conductive supramolecular polymer network that simultaneously exhibits both electronic and ionic conductivity while maintaining tissue‐mimetic mechanical properties, providing an ideal electronic interface with the human body, is introduced. Rational design of an ultrahigh affinity host–guest ternary complex led to binding affinities (>1013 M‐2) of over an order of magnitude greater than previous reports. Embedding these complexes as dynamic cross‐links, coupled with in situ synthesis of a conducting polymer, resulted in electrically conductive supramolecular polymer networks with tissue‐mimetic Young's moduli (<5 kPa), high stretchability (>500%), rapid self‐recovery and high water content (>84%). Achieving such properties enabled fabrication of intrinsically‐stretchable stand‐alone bioelectrodes, capable of accurately monitoring electromyography signals, free from any rigid materials.
Integration of non‐covalent cross‐links and conducting polymers enables access to an electrically conductive supramolecular polymer network (E‐SPN) exhibiting tissue‐mimetic softness and stretchablity. The resultant material allows for fabrication of intrinsically‐stretchable, stand‐alone bioelectrodes, capable of comfortably and accurately measuring electromyography signals in real time. This research will offer a step toward the design and construction of next‐generation, skin‐like bioelectronics.