Biocompatible sensing and adhesive interfaces enabled by functionalized biomaterials for wearable healthcare applications

Abstract

Wearable bioelectronics have emerged as powerful tools for continuous monitoring, providing non-invasive and personalized healthcare solutions. This thesis investigates the potential of functionalized biomaterials in the development of biocompatible wearable sensing and adhesive interfaces for biomedical applications.

Specifically, the thesis addresses challenges associated with the biosafety and sustainability of inorganic perovskites or organic piezopolymers by exploring silk fibroin (SF) as a biocompatible alternative for wearable piezoelectric sensors. However, SF's inherent piezoelectricity is relatively weak, limiting its practical sensing applications. The objective is to enhance the piezoelectricity of SF through the in-situ growth of non-toxic metal-free perovskite (MFP), resulting in the fabrication of organic and flexible SF-MFP composite films. The incorporation of MFP influences the morphology and crystallinity of the SF-MFP films, leading to an improved piezoelectric response. These sensors exhibit linearity, stability, and fast response times, successfully detecting joint bending and muscle movements in human subjects, thus demonstrating their suitability for wearable bioelectronics.

In addition, achieving a wearable adhesive that seamlessly interfaces with the skin, maintains breathability, and provides reliable adhesion on sweaty or wet skin remains a challenge. Catechol-based hydrogels have shown exceptional adhesive properties in wet environments; however, their susceptibility to oxidation limits their adhesive strength and shelf life. Furthermore, most hydrogel systems are incompatible with silicone-based wearable sensors. This thesis introduces a unique and novel approach through the development of an elastomer-supramolecular gel that creates a flexible, robust, and adhesive interface. The developed interface demonstrates strong adhesion to wet porcine skin within a minute of light pressure application. By addressing the challenges of achieving biocompatible and reliable skin adhesion, this research paves the way for the development of skin-friendly and efficient wearable interfaces.

In conclusion, this thesis offers valuable insights and potential solutions for enhancing the performance, comfort, and biosafety of wearables in various biomedical applications.

Date of Award	2024
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	I-ming HSING (Supervisor)