2D to 3D Manipulation and Assembly of Microstructures Using Optothermally Generated Surface Bubble Microrobots

Hydrogel microstructures that encapsulate cells can be assembled into tissues and have broad applications in biology and medicine. However, 3D posture control for a single arbitrary microstructure remains a challenge. A novel 3D manipulation and assembly technique based on optothermally generated bubble robots is proposed. The generation, rate of growth, and motion of a microbubble robot can be controlled by modulating the power of a laser focused on the interface between the substrate and a fluid. In addition to 2D operations, bubble robots are able to perform 3D manipulations. The 3D properties of hydrogel microstructures are adjusted arbitrarily, and convex and concave structures with different heights are designed. Furthermore, annular micromodules are assembled into 3D constructs, including tubular and concentric constructs. A variety of hydrogel microstructures of different sizes and shapes are operated and assembled in both 2D and 3D conformations by bubble robots. The manipulation and assembly methods are simple, rapid, versatile, and can be used for fabricating tissue constructs.

包裹细胞的水凝胶微结构可组装成组织，在生物学和医学领域有广泛应用。然而，对单个任意微结构进行三维姿态控制仍然是一个挑战。一种基于光热产生的气泡机器人的新型三维操作和组装技术被提出。通过调节聚焦在基底和流体界面上的激光功率，可以控制微气泡机器人的产生、生长速率和运动。除了二维操作，气泡机器人还能够进行三维操作。水凝胶微结构的三维特性可任意调整，并设计出不同高度的凸形和凹形结构。此外，环形微模块被组装成三维结构，包括管状和同心结构。气泡机器人以二维和三维构象操作和组装了各种不同大小和形状的水凝胶微结构。这种操作和组装方法简单、快速、通用，可用于制造组织构建体。