Light-Fueled In-Operando Shape Reconfiguration, Fixation, and Recovery of Magnetically Actuated Microtextured...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Covalent adaptable networks (CANs) offer reprocessability through dynamic bond exchange.
• Conventional CANs require high heat and pressure for processing due to insufficient viscosity reduction.
• Existing methods for shape fixation often rely on external binders.

Purpose of the Study:

• To develop a UV-assisted processing method for CANs at room temperature.
• To enable contactless 3D microfabrication and shape control using CANs.
• To investigate the mechanism of UV- and heat-induced dynamic bond exchange.

Main Methods:

• Synthesis of disulfide-bonded CANs.
• UV irradiation and thermal treatment for processing.
• Molecular dynamics (MD) simulations to study bond exchange mechanisms.
• Incorporation of magnetic NdFeB particles for magnetomechanical actuation.
• Masking techniques for spatiotemporal control.

Main Results:

• UV irradiation at room temperature accelerates stress relaxation in CANs, similar to thermal activation above T_v.
• Successful magnetomechanical actuation and in-operando shape reconfiguration of CAN/NdFeB microarrays.
• Demonstration of binder-free shape fixation and reversible recovery of original architectures.
• Contactless, spatiotemporal control over microarchitectures via photoresponsive dynamic bond exchange.

Conclusions:

• UV-assisted processing provides a facile route for CANs at room temperature.
• The developed CAN system enables advanced 3D microfabrication with precise shape control.
• This approach eliminates the need for binders and external pressure in shape fixation.