Controlled macroscopic shape evolution of self-growing polymeric materials

Area of Science:

• Materials Science
• Polymer Chemistry
• Soft Matter Physics

Background:

• Living organisms grow by absorbing nutrients and integrating mass, enabling shape changes for adaptation.
• Existing synthetic dynamic polymers often lack controlled global geometric transformation during growth.
• Mimicking biological growth in synthetic materials remains a significant challenge.

Purpose of the Study:

• To develop a method for controlled, growth-induced shape transformation in synthetic materials.
• To enable significant mass transport and reshaping through spatially controlled polymerization.
• To create soft materials that can autonomously change shape during growth.

Main Methods:

• Utilized anionic ring-opening polymerization (anionic ROP) of octamethylcyclotetrasiloxane (D4) in silicone systems.
• Employed a strong base catalyst to initiate and control polymerization.
• Demonstrated shape transformation by applying monomer mixtures to specific sample areas.

Main Results:

• Successfully transformed a flat square silicone sample into a sphere through controlled growth, without remolding.
• Achieved precise control over the size and shape of growing polymeric objects.
• Demonstrated modulation of mechanical properties, self-healing ability, and growth site availability.

Conclusions:

• The developed method enables controlled, growth-induced shape transformation in synthetic materials via spatially controlled polymerization.
• This approach offers a novel pathway for creating soft materials with tailored shapes and surface morphologies.
• The technique provides a platform for designing materials that can autonomously adapt their form through mass transport and integration.