Electrothermally Driven Hydrogel-on-Flex-Circuit Actuator for Smart Steerable Catheters

Area of Science:

• Biomedical Engineering
• Materials Science
• Robotics

Background:

• Catheter navigation in vascular networks is challenging.
• Existing steerable catheters have limitations in bending range and control.

Purpose of the Study:

• To develop an active catheter-tip device for controlled steering.
• To enable navigation through complex vascular anatomies.

Main Methods:

• Integrating a temperature-responsive polymer (poly(N-isopropylacrylamide) hydrogel - PNIPAM) onto a microfabricated flexible heater strip.
• Utilizing a low-cost flex-circuit manufacturing process for the heater.
• Photo-polymerizing PNIPAM on a polyimide film with a micropatterned heater.

Main Results:

• The device demonstrated adjustable bending angles up to 200° upon heater activation.
• Uniform heat distribution with minimal temperature variation (<2 °C) was observed.
• Actuation showed consistent and reproducible temporal responses and bending forces.

Conclusions:

• The prototyped device offers a promising approach for controlled catheter steering.
• The technology enables significantly larger bending angles compared to existing smart-material-based catheters.
• This proof-of-concept validates the potential for enhanced catheter navigation in medical procedures.