Novel Operation Mechanism and Multifunctional Applications of Bubble Microrobots.

Microrobots have emerged as powerful tools for manipulating particles, cells, and assembling biological tissue structures at the microscale. However, achieving precise and flexible operation of arbitrary-shaped microstructures in three-dimensional (3D) space remains a challenge. In this study, we propose three novel operation methods based on bubble microrobots to enable delicate and multifunctional manipulation of various microstructures. These methods include 3D turnover, fixed-point rotation, and 3D ejection. By harnessing the combined principles of the effect of the heat flow field and surface tension of an optothermally generated bubble, the bubble microrobot can perform tasks such as flipping an SIA humanoid structure, rotating a bird-like structure, and launching a hollow rocket-like structure. The proposed multi-mode operation of bubble microrobots enables diverse attitude adjustments of microstructures with different sizes and shapes in both two and three-dimensional spaces. As a demonstration, a biological microenvironment of brain glioblastoma (GBM) is constructed by the bubble microrobot. The simplicity, versatility, and flexibility of our proposed method hold great promise for applications in micromanipulation, assembly, and tissue engineering. This article is protected by copyright. All rights reserved.