Imperceptible epidermal sensors for sweat biomarkers detection enabled by ultrahigh molecular weight polyethylene nanofibrous membrane

Abstract

The primary characteristic of epidermal electronics is their imperceptibility, a critical feature that guarantees the seamless integration of electronic components without disrupting the natural physiological processes of the human body. Polymer film substrates play a crucial role in accommodating various functionalities such as flexibility, stretchability, and permeability, thereby contributing significantly to achieving overall imperceptibility. This study explores the potentials of Ultrahigh Molecular Weight Polyethylene (UHMWPE) nanofibrous membranes in the development of epidermal biosensors for the detection of sweat biomarkers. The research methodology involves three essential stages including an in-depth exploration of the interface, the integration of functional materials to enhance properties, and the evaluation of performance for real-time biomarker detection. 1)The UHMWPE nanofibrous membrane showcases essential properties serving as a "pseudo skin". Its low flexural rigidity allows it to adhere seamlessly to the skin through van der Waals interactions, while its high porosity and hydrophobic characteristics prevent salt ion accumulation at the bio-electronic interface. This structure facilitates the transport of sweat biomarkers through interconnected nanopores resembling sweat glands, enhancing the sensitivity of biomarker detection. 2)Two distinct functionalization techniques are proposed to enhance the UHMWPE membrane's selectivity and conductivity while maintaining skin-comfortability and permeability. The Janus MIP@UHMWPE composite membrane, featuring a monolayer of MIP nanoparticles on the surface, displays selective adsorption towards target molecule. In addition, the PEDOT@PVA-PE composite membrane, with PEDOT embedded within the fibrous network, demonstrates sufficient conductivity. The in-situ synthesis approach provides precise control over thickness and porosity, effectively balancing conformability, permeability, and functionality. 3)By employing a combination of fabrication techniques, Pt electrodes, PEDOT channels, MIP nanoparticles, and immobilized GOx are incorporated into the UHMWPE membrane to generate specific configurations. Subsequently, cortisol and glucose sensors are developed on the UHMWPE membrane and assessed, revealing a notable sensitivity to the targeted biomarkers. The discreet design of the sensor enables imperceptible detection, maintaining metabolic functions and showing potential for sophisticated biosensing applications in healthcare. This research lays the foundation for harnessing state-of-the-art sensor technologies to improve non-invasive, precise, and user-friendly biosensing capabilities, thereby propelling advancements in healthcare monitoring and personalized diagnostic methodologies.

Date of Award	2024
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	Ping GAO (Supervisor) & Xijun HU (Supervisor)