Multifunctional, Degradable Wearable Sensors Prepared with an Initiator and Crosslinker-Free Method.

Area of Science:

• Materials Science
• Biomedical Engineering
• Polymer Chemistry

Background:

• Current zwitterionic hydrogel wearable sensors face limitations including poor mechanical properties, toxicity from initiators, and insufficient degradation.
• These drawbacks hinder their practical application and raise environmental concerns regarding electronic waste.

Purpose of the Study:

• To develop an initiator and crosslinker-free zwitterionic hydrogel with improved properties for wearable sensors.
• To create an eco-friendly and biodegradable alternative to existing hydrogel sensor technologies.

Main Methods:

• Fabrication of polyethylene glycol (PEG)@poly[2-(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl) (PSBMA) interpenetrating polymer network (IPN) hydrogels.
• Utilized sunlight-induced self-polymerization with non-covalent crosslinking via electrostatic interactions and hydrogen bonding.
• Characterized hydrogel properties including mechanical strength, stretchability, biocompatibility, antibacterial activity, adhesion, and ionic conductivity.

Main Results:

• The PEG@PSBMA IPN hydrogel demonstrated tissue-like softness, high stretchability (∼2344.6%), and enhanced fracture strength (∼39.5 kPa).
• The hydrogel exhibited excellent biocompatibility, antibacterial properties, reliable adhesion, and good ionic conductivity.
• Wearable sensors based on the IPN hydrogel showed sensitive and stable real-time monitoring of human activities and degraded completely in saline solution within 8 hours.

Conclusions:

• The developed initiator and crosslinker-free approach successfully created advanced zwitterionic hydrogels with superior performance.
• This physically crosslinked hydrogel offers a promising, eco-friendly material for next-generation wearable electronic devices.
• The rapid degradability addresses electronic waste concerns, paving the way for sustainable wearable technology.