Hashimoto Sayaka, Uenobo Yuki, Takao Ryota, Yuyama Ken-Ichi, Shoji Tatsuya, Linklater Denver P, Ivanova Elena, Juodkazis Saulius, Kameyama Tatsuya, Torimoto Tsukasa, Tsuboi Yasuyuki
Division of Molecular Materials Science, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan.
Department of Chemistry, Faculty of Science, Kanagawa University, 2946 Tsuchiya, Hiratsuka 259-1293, Japan.
ACS Appl Mater Interfaces. 2021 Jun 16;13(23):27586-27593. doi: 10.1021/acsami.1c04929. Epub 2021 Jun 4.
Optical tweezers enable the manipulation of micro- and nanodielectric particles through entrapment using a tightly focused laser. Generally, optical trapping of submicron size particles requires high-intensity light in the order of MW/cm. Here, we demonstrate a technique of stable optical trapping of submicron polymeric beads on nanostructured titanium surfaces (black-Ti) without the use of lasers. Fluorescent polystyrene beads with a diameter = 20-500 nm were successfully trapped on black-Ti by low-intensity focused illumination of incoherent light at λ = 370 m from a Hg lamp. Light intensity was 5.5 W/cm, corresponding to a reduced light intensity of 6 orders of magnitude. Upon switching off illumination, trapped particles were released from the illuminated area, indicating that trapping was optically driven and reversible. Such trapping behavior was not observed on nonstructured Ti surfaces or on nanostructured silicon surfaces. Thus, the Ti nanostructures were demonstrated to play a key role.
光镊技术通过使用紧聚焦激光捕获来实现对微米和纳米介电粒子的操控。一般来说，捕获亚微米尺寸的粒子需要兆瓦每平方厘米量级的高强度光。在此，我们展示了一种在不使用激光的情况下，在纳米结构钛表面（黑色钛）稳定捕获亚微米聚合物微珠的技术。直径为20 - 500纳米的荧光聚苯乙烯微珠通过来自汞灯、波长为370纳米的非相干光的低强度聚焦照射成功地被捕获在黑色钛表面。光强为5.5瓦每平方厘米，相当于光强降低了6个数量级。关闭照明后，被捕获的粒子从照明区域释放，这表明捕获是由光驱动的且是可逆的。在非结构化钛表面或纳米结构硅表面未观察到这种捕获行为。因此，证明了钛纳米结构起到了关键作用。
