Technology of fabrication and applications of 3D micro-nano-architectures based on aero-GaN

Abstract

The GaN tubular microstructures, with diameter of 2-10 μm, the length from 20 to 100 μm and the wall thickness several tens of nanometers, show interesting microfluidic properties. A pellet of micro-tubes and hollow micro-tetrapods exhibit hydrophilicity under tension and hydrophobicity when compressed against water [1]. The hydrophilicity is attributed to the nanoscale free ends and internal walls of the tetrapod arms, which consist of ultrathin ZnO layer, and the hydrophobicity to the external GaN walls. Self-assembling tetrapods on the water surface enabled us to develop a proof-of-concept device, namely of stretchable and highly energy efficient self-propelled liquid marbles exhibiting fast velocity of rotation, pulsed rotation [2] and exceptional mechanical robustness. These findings on Gallium Nitride nanostructures have great potential to the development of innovative biomedical engineering applications e.g. the development of cellular based therapy concept, remotely controlled tissue/organs engineering, energy-efficient self-propelled micro-electromechanical structures, etc.