Covalent Adaptable Microstructures via Combining Two?Photon Laser Printing and Alkoxyamine Chemistry: Toward Living 3D Microstructures

Manufacturing programmable materials, whose mechanical properties can be adapted on demand, is highly desired for their application in areas ranging from robotics, to biomedicine, or microfluidics. Herein, the inclusion of dynamic and living bonds, such as alkoxyamines, a printable formulation suitable two-photon 3D laser printing exploited. On one hand, taking advantage covalent character nitroxide exchange reaction investigated. As consequence, reduction Young´s Modulus by 50%, measured nanoindentation. other due its “living” characteristic, chain extension becomes possible via mediated polymerization. In particular, polymerization styrene results not only dramatic increase volume (?8 times) printed microstructure but also an Young's two orders magnitude (from 14 MPa 2.7 GPa), while maintaining shape including fine structural details. Thus, approach introduces new dimension enabling create microstructures with dynamically tunable size properties.