In this paper, we demonstrate nanoparticle flow control using an optical force in a confined nanospace. Using nanofabrication technologies, all-quartz-glass nanoslit channels with a sudden contraction are developed. Because the nanoslit height is comparable to the nanoparticle diameter, the motion of particles is restricted in the channel height direction, resulting in almost two-dimensional particle motion. The laser irradiates at the entrance of the sudden contraction channel, leading the trapped nanoparticles to form a cluster. As a result, the translocation of nanoparticles into the contraction channel is suppressed. Because the particle translocation restarts when the laser irradiation is stopped, we can control the nanoparticle flow into the contraction channel by switching the trapping and release of particles, realizing an intermittent flow of nanoparticles. Such a particle flow control technique in a confined nanospace is expected to improve the functions of nanofluidic devices by transporting a target material selectively to a desired location in the device.

在本文中，我们演示了在受限的纳米空间中利用光力进行的纳米粒子流控制。使用纳米制造技术，开发了具有突然收缩功能的全石英玻璃纳米狭缝通道。因为纳米缝的高度与纳米颗粒的直径相当，所以颗粒的运动在通道高度方向上受到限制，从而导致几乎二维的颗粒运动。激光在突然收缩的通道的入口处照射，导致捕获的纳米颗粒形成簇。结果，抑制了纳米颗粒向收缩通道的移位。由于停止激光照射后，粒子的重新定位会重新开始，因此我们可以通过切换粒子的捕获和释放来控制纳米粒子流入收缩通道，实现纳米颗粒的间歇流动。在受限的纳米空间中的这种粒子流控制技术有望通过选择性地将目标材料传输到设备中的所需位置来改善纳米流体设备的功能。