Development of Hydrogel-Based Flexible Wearable Sensors for Biotechnological Applications

Abstract

The advent of 5G, the Internet of Things (IoT), and artificial intelligence (AI) has ushered us into an era of ubiquitous connectivity. Among these technological advancements, flexible wearable sensors have become increasingly vital due to their ability to interface directly with the human body and collect critical data. Traditionally, these sensors utilize substrates such as polyvinyl alcohol (PVA), polydimethylsiloxane (PDMS), and polyacrylamide (PAAm), integrated with conductive materials like metal nanoparticles, graphene oxide, and carbon nanotubes. Their operation typically involves the translation of mechanical deformations into electrical signals for real-time monitoring. As the applications of these sensors broaden, there is a growing requirement for enhanced functionality, including higher sensitivity, self-healing capabilities, and substantial flexibility. Hydrogels, characterized by their gelatinous, three-dimensional polymer networks, have emerged as promising materials for crafting next-generation sensors. Their physical properties closely resemble human tissue, providing both excellent stretchability and electrical conductivity. However, conventional hydrogels, primarily those that are chemically cross-linked, often lack necessary features like adhesion, self-healing, and environmental stability, limiting their practicality in wearable applications. This study addresses these limitations by synthesizing a novel hydrogel composed of titanium carbide and polyacrylic acid (MXene/PAA) using a sol-gel process. To enhance their environmental resilience, these hydrogels underwent a solvent replacement method, which imbued them with anti-freezing properties and improved moisture retention. The potential applications of these hydrogels in flexible wearable sensors were thoroughly explored, emphasizing their improved performance across various temperatures and mechanical stresses. This research paves the way for deploying hydrogel-based sensors in a wide array of biotechnological applications, providing robust, reliable data connectivity directly from the user's body.