Bio-Inspired Magnetically Controlled Reversibly Actuating Multimaterial Fibers

Area of Science:

• Materials Science
• Robotics
• Biomimicry

Background:

• Plant movements, like tendril coiling, inspire robotic actuator designs.
• Multimaterial systems with varying elastic moduli are key to mimicking these movements.

Purpose of the Study:

• To develop magnetically controllable multimaterial fibers (MMFs) that act as artificial tendrils.
• To achieve reversible coiling and uncoiling actuation in MMFs using alternating magnetic fields.

Main Methods:

• Fabrication of MMFs with a poly[ethylene-co-(vinyl acetate)] (PEVA) core and a magnetic nanocomposite shell.
• Utilizing the core's temperature-dependent expansion/contraction and the shell's inductive heating for actuation.
• Investigating the effect of magnetic field application and removal on MMF coiling behavior.

Main Results:

• MMFs demonstrated magnetically triggered reversible coiling and uncoiling.
• A degree of coiling (N) of 0.8 ± 0.2 was achieved upon magnetic field application.
• Reversible coiling change (Δn) of 2 ± 0.5 was observed upon magnetic field removal.
• Composites required ≥ 15 wt% magnetic nanoparticles (mNPs) for effective inductive heating and movement.

Conclusions:

• Developed MMFs provide magnetically controlled, remote, and reversible actuation for artificial tendrils.
• These MMFs show potential as fiber actuators in soft robotics applications.
• The study highlights the successful biomimicry of plant tendril movements using advanced material systems.