Dual-Functionality, Bio-Friendly Artificial Muscles for Actuation and Motion Sensing in Smart Wearable Systems

Area of Science:

• Materials Science
• Soft Robotics
• Wearable Electronics

Background:

• Carbon nanotube (CNT) yarns offer unique electrochemical and mechanical properties.
• Developing biofriendly, air-operating artificial muscles is crucial for advanced robotics and wearables.
• Ion-selective materials are key for precise electrochemical control in soft devices.

Purpose of the Study:

• To create a unipolar coiled CNT yarn artificial muscle functioning as both an actuator and a strain sensor.
• To investigate the biofriendly, air-operating capabilities of this novel electrochemical platform.
• To demonstrate its potential in smart fabrics, wearable electronics, and adaptive soft robotics.

Main Methods:

• Fabrication of coiled CNT yarn electrodes coated with complementary ion-selective eutectogels.
• Utilizing deep eutectic solvents (DES) for selective ion transport.
• Employing Poisson-Nernst-Planck modeling to understand strain-induced ion redistribution.

Main Results:

• The device achieved a 2.9% reversible contractile stroke in actuation mode and operated as a self-powered strain sensor with 0.5 mV/% sensitivity.
• Woven auxetic structures demonstrated parallel actuation and strain monitoring, yielding 4 mV OCV signals at 10% extension.
• A wireless wearable armband for real-time motion monitoring was successfully demonstrated.

Conclusions:

• The developed CNT yarn artificial muscle platform is a versatile, biofriendly, and air-operating solution for actuation and sensing.
• Its unique properties enable applications in smart textiles, wearable devices, and soft robotic systems.
• This research paves the way for next-generation adaptive and responsive electronic materials.