A Tissue Adhesion-Controllable and Biocompatible Small-Scale Hydrogel Adhesive Robot

Area of Science:

• Biomedical Engineering
• Materials Science
• Robotics

Background:

• Minimally invasive medical interventions using wireless small-scale robots require robust tissue adhesion and controlled detachment.
• Existing technologies face challenges in achieving both strong adhesion and easy, controlled detachment on biological tissues.

Purpose of the Study:

• To develop a small-scale soft robot with an octopus-inspired hydrogel adhesive (OHA) for effective tissue adhesion and controlled detachment in biomedical applications.
• To overcome the limitations of current robotic systems in achieving reliable underwater adhesion and detachment.

Main Methods:

• Designed a biocompatible hydrogel adhesive inspired by octopus suckers, utilizing hydrogels with varying Young's moduli to prevent pattern collapse during preloading.
• Incorporated poly(N-isopropylacrylamide) hydrogel within a polyethylene glycol diacrylate hydrogel structure to create dome-like protuberances for enhanced adhesion.
• Leveraged the temperature-dependent volume change property of poly(N-isopropylacrylamide) for controlled detachment.

Main Results:

• The octopus-inspired hydrogel adhesive (OHA) demonstrated strong wet adhesion to biological tissues, even underwater.
• The robot exhibited easy and controlled detachment triggered by temperature variations.
• Successful implementation of biomedical functions by the small-scale soft OHA robot inside the body was demonstrated.

Conclusions:

• The developed OHA robot provides a promising solution for strong, repeatable tissue attachment and controlled detachment in underwater environments.
• This technology paves the way for future wireless soft miniature robots capable of advanced minimally invasive medical interventions.
• The OHA robot's capabilities enhance the potential for in-body robotic applications requiring precise tissue manipulation.