Poly(N-isopropylacrylamide) hydrogel crosslinked with laponite and loaded with Au nanoparticles for sensitive motion sensor with improved mechanical stability, conductivity, and controllable releasing ability
Samaneh Khodami, Mosayeb Gharakhloo, Serife Dagdelen, Piotr Fita, Marcin Karbarz, Zbigniew Stojek
Abstract
Hydrogels, although promising as motion sensors and drug delivery platforms, suffer from limitations such as insufficient stretchability, low toughness, poor fatigue resistance, inadequate conductivity, and limited control over drug release. This study aimed to develop a novel multifunctional nanocomposite hydrogel capable of overcoming these limitations and suitable for wearable sensing and therapeutic applications. Novel nanocomposite hydrogels (P(NIPA_Lap_AuNP)) were synthesized by incorporating gold nanoparticles into poly( N -isopropylacrylamide) hydrogel crosslinked with laponite. The hydrogel was evaluated through mechanical characterization, bending angle and strain sensitivity tests, and controlled drug release experiments. The best sample (P(NIPA_Lap_2AuNP)) demonstrated enhanced tensile strength (83 kPa) and high stretchability (1520%), good toughness (502 kJ·m⁻³), and fatigue resistance as well as notable strain sensitivity (GF: 8.1 at 250% strain) and significant responsiveness to bending. Moreover, the hydrogel showed promising, controllable drug release performance suitable for cancer therapy using near-infrared (NIR) laser stimulation. Our findings indicate that the developed P(NIPA_Lap_AuNP) hydrogel represents an effective platform for wearable motion sensors and multifunctional biomedical applications, particularly in smart wearable therapeutic patches.