Ding Hongru, Kollipara Pavana Siddhartha, Kim Youngsun, Kotnala Abhay, Li Jingang, Chen Zhihan, Zheng Yuebing
Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA.
Sci Adv. 2022 Jun 17;8(24):eabn8498. doi: 10.1126/sciadv.abn8498. Epub 2022 Jun 15.
Rotation of micro/nano-objects is important for micro/nanorobotics, three-dimensional imaging, and lab-on-a-chip systems. Optical rotation techniques are especially attractive because of their fuel-free and remote operation. However, current techniques require laser beams with designed intensity profile and polarization or objects with sophisticated shapes or optical birefringence. These requirements make it challenging to use simple optical setups for light-driven rotation of many highly symmetric or isotropic objects, including biological cells. Here, we report a universal approach to the out-of-plane rotation of various objects, including spherically symmetric and isotropic particles, using an arbitrary low-power laser beam. Moreover, the laser beam is positioned away from the objects to reduce optical damage from direct illumination. The rotation mechanism based on opto-thermoelectrical coupling is elucidated by rigorous experiments combined with multiscale simulations. With its general applicability and excellent biocompatibility, our universal light-driven rotation platform is instrumental for various scientific research and engineering applications.
微纳物体的旋转对于微纳机器人技术、三维成像以及芯片实验室系统而言至关重要。光学旋转技术因其无需燃料且可远程操作而格外具有吸引力。然而，当前的技术需要具有特定强度分布和偏振的激光束，或者需要具有复杂形状或光学双折射的物体。这些要求使得使用简单的光学装置来实现许多高度对称或各向同性物体（包括生物细胞）的光驱动旋转具有挑战性。在此，我们报告了一种通用方法，可利用任意低功率激光束使包括球对称和各向同性粒子在内的各种物体进行面外旋转。此外，激光束与物体保持一定距离，以减少直接照射造成的光学损伤。通过严谨的实验结合多尺度模拟，阐明了基于光热电耦合的旋转机制。凭借其广泛的适用性和出色的生物相容性，我们的通用光驱动旋转平台对各种科研和工程应用具有重要意义。
