Biocatalytic 3D Actuation in Liquid Crystal Elastomers via Enzyme Patterning

Area of Science:

• Materials Science
• Biochemistry
• Polymer Chemistry

Background:

• Liquid crystal elastomers (LCEs) are known for large shape changes upon thermal stimuli.
• Developing room-temperature, specific triggers for LCEs is an active research area.
• Biocatalytic materials offer precise control and stimuli-specific responses.

Purpose of the Study:

• To fabricate biocatalytic LCEs responsive to urea at room temperature.
• To investigate the mechanism of enzyme-induced shape transformation in LCEs.
• To demonstrate spatial control over LCE actuation for 3D shape programming.

Main Methods:

• Covalent immobilization of urease enzyme within hydrogen-bonded LCE networks.
• Exposure of LCEs to urea solution and monitoring of strain response.
• Spatially patterning urease on LCE surfaces for localized actuation.
• Investigating the role of salt concentration in preventing network bridging.

Main Results:

• Fabricated LCEs showed contractile strains up to 36% in response to base.
• Urease-catalyzed ammonia generation disrupted LCE supramolecular order and reduced liquid crystalline order upon urea exposure.
• Actuation strain was tunable by urea concentration and exposure time.
• Spatially patterned LCEs transformed into 3D structures (curl, arch, accordion) triggered by urea.
• Salt presence was crucial for preventing ammonium ion bridging and enabling 3D shape changes.

Conclusions:

• Biocatalytic LCEs provide a novel platform for stimuli-responsive materials triggered by specific biochemical reactions.
• Enzyme immobilization within LCEs translates biocatalytic activity into macroscopic, controllable 3D shape transformations.
• These materials hold potential for applications in cell culture, medicine, and antifouling technologies.