Shape-changing polymer micro-origami with fully reprogrammable spatio-temporal folding

• Applicants: Professor Dr. Andreas Fery; Professor Dr. Leonid Ionov
• Subject Area: Polymer Materials
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 424722442

Shape-changing materials are highly promising for design of 3D microelectronics, biomaterials, robotic microsystems and microfluidic systems, smart textiles, optics, to mention just the most prominent examples. Within this field, polymer origami, which relies on structures, which fold in response to external triggers, has turned out as a highly promising approach. However, so far, it still suffers from several fundamental restrictions: • rather than undergoing a programmed sequence of folding events, usually the structures can only switch between a “globally folded” and “globally unfolded” state and • folded or un-folded states cannot always be locked in their folded / unfolded configuration. This project aims to overcome these restrictions and introduce fully flexible programming of folding behavior. Freely programmed folding will be achieved using hydrogel/solid polymer/hydrogel trilayer sandwich, which contain photosensitive nanoparticles. The nanoparticles provide possibility to locally actuate the film by illumination. Two stimuli-responsible hydrogels layers are responsive for bending of the film in different direction. The solid polymer layer with low melting point, which is between hydrogel layers, is responsible for freezing and unfreezing of folding. Our approach will allow combining of advantages of shape-memory polymers with advantages of hydrogels and elimination of their disadvantages. In this project, we will fundamentally understand cooperative interactions of different kinds of shape-changing materials as well as their interaction with externally controlled nanoparticles. The project combines complimentary expertizes of two groups (Ionov and Fery) in shape-changing materials and optically active nanoparticles, as well as polymer/nanoparticle hybrid materials. The project will considerable advance field of shape-changing materials that will allow development of new technologies.

• DFG Programme: Research Grants