Light is a precious resource that nature has given to human beings. Converting green, recyclable light energy into the mechanical energy of a micromotor is undoubtedly an exciting challenge. However, the performance of current light-induced micromotor devices is unsatisfactory, as the light-to-work conversion efficiency is only 10−15–10−12. In this paper, we propose and demonstrate a laser-induced rotary micromotor operated by Δα-type photopheresis in pure liquid glycerol, whose energy conversion ratio reaches as high as 10−9, which is 3–6 orders of magnitude higher than that of previous light-induced micromotor devices. In addition, we operate the micromotor neither with a light field carrying angular momentum nor with a rotor with a special rotating symmetrical shape. We just employ an annular-core fiber to configure a conical-shaped light field and select a piece of graphite sheet (with an irregular shape) as the micro-rotor. The Δα-type photophoretic force introduced by the conical-shaped light field drives the rotation of the graphite sheet. We achieve a rotation rate up to 818.2 r/min, which can be controlled by tuning the incident laser power. This optical rotary micromotor is available for twisting macromolecules or generating vortex and shear force in a medium at the nanoscale.

中文翻译：

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高能量转换效率的激光感应旋转微电机

光是大自然赋予人类的宝贵资源。将绿色、可回收的光能转化为微电机的机械能无疑是一项激动人心的挑战。然而，目前光致微电机器件的性能并不令人满意，因为光到工作的转换效率仅为 10-15-10-12。在本文中，我们提出并展示了一种由纯液态甘油中的 Δα 型光分离法操作的激光诱导旋转微电机，其能量转化率高达 10-9，比以往高出 3-6 个数量级。光诱导微电机装置。此外，我们既不使用承载角动量的光场，也不使用具有特殊旋转对称形状的转子来操作微电机。我们只是采用环形纤芯光纤配置锥形光场，选择一块石墨片（形状不规则）作为微转子。锥形光场引入的Δα型光泳力驱动石墨片旋转。我们实现了高达 818.2 r/min 的转速，这可以通过调整入射激光功率来控制。这种光学旋转微电机可用于扭曲大分子或在纳米级介质中产生涡流和剪切力。