Sugiura Tadao, Maeda Saki, Honda Ayae
Graduate School of Information Science, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192 Japan.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:4479-81. doi: 10.1109/EMBC.2012.6346961.
Optical tweezers which enables to trap micron to nanometer sized objects by radiation pressure force is utilized for manipulation of particles under a microscope and for measurement of forces between biomolecules. Weak force of optical tweezers causes some limitations such as particle adhesion or steric barrier like lipid membrane in a cell prevent further movement of objects. For biomedical applications we need to overcome these difficulties. We have developed a technique to exert strong instantaneous force by use of a pulse laser beam and to assist conventional optical tweezers. A pulse laser beam has huge instantaneous laser power of more than 1000 times as strong as a conventional continuous-wave laser beam so that the instantaneous force is strong enough to break chemical bonding and molecular force between objects and obstacles. We derive suitable pulse duration for pulse assist of optical tweezers and demonstrate particle manipulation in difficult situations through an experiment of particle removal from sticky surface of glass substrate.
光镊能够通过辐射压力捕获微米到纳米尺寸的物体，被用于在显微镜下操纵粒子以及测量生物分子之间的力。光镊的弱力会导致一些限制，比如粒子粘附或细胞中的脂质膜等空间位垒会阻止物体进一步移动。对于生物医学应用，我们需要克服这些困难。我们已经开发出一种技术，通过使用脉冲激光束施加强大的瞬时力，并辅助传统光镊。脉冲激光束具有比传统连续波激光束强1000倍以上的巨大瞬时激光功率，使得瞬时力强大到足以打破物体与障碍物之间的化学键和分子力。我们推导出了适合光镊脉冲辅助的脉冲持续时间，并通过从玻璃基板粘性表面去除粒子的实验，展示了在困难情况下的粒子操纵。
