β-Cyclodextrin-Based Ultrahigh Stretchable, Flexible, Electro- and Pressure-Responsive, Adhesive, Transparent...

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Development of advanced hydrogels with multiple stimuli-responsive properties is crucial for novel sensor applications.
• Beta-cyclodextrin (β-CD) based hydrogels offer unique structural and functional advantages.
• Existing flexible sensors often lack sufficient biocompatibility, transparency, or multi-responsiveness.

Purpose of the Study:

• To synthesize and characterize a novel multiple-stimuli-responsive hydrogel based on β-cyclodextrin.
• To fabricate a flexible, transparent, and biocompatible pressure sensor using the synthesized hydrogel.
• To evaluate the sensor's performance in monitoring human motion and its potential for drug delivery.

Main Methods:

• Polymerization of acrylamide (AAm) and N-hydroxy methyl acrylamide (HMAm) on β-cyclodextrin (β-CD).
• Characterization of hydrogel properties including stretchability, transparency, responsiveness, and biocompatibility.
• Fabrication and testing of a flexible pressure sensor for human motion detection and drug release studies.

Main Results:

• The synthesized β-CD-g-(pAAm/pHMAm) hydrogel exhibited ultrahigh stretchability (>6000%), high transparency (>90%), and multiple stimuli-responsiveness (electro, pressure, thermo).
• A flexible pressure sensor demonstrated high sensitivity (0.053 kPa⁻¹), fast response time (130-210 ms), and stability (5000 cycles).
• The hydrogel patch showed potential for sustained topical release of gentamicin sulfate (∼80.8% in 48 h) and biocompatibility.

Conclusions:

• The developed β-CD-g-(pAAm/pHMAm) hydrogel is a promising material for advanced flexible electronic devices.
• The fabricated sensor effectively monitors diverse human physiological motions and offers drug delivery capabilities.
• This multi-functional hydrogel holds significant potential for wearable electronics and biomedical applications.