Presentation Information

[24a-P01-7]Optically Evolved Swarming of Gold Nanoparticles within 3D Printed Microchannel

〇(M1)PIN HSUN HUANG1, Chih-Hao Huang1, Mu-En Li1, Henryk Witek1, Peng-Chin Tsai1, Hsin-Ni Wu1, Ming-Chia Li1, Hiroshi Masuhara1 (1.Nat'l Yang Ming Chiao Tung Univ., Taiwan)


optical trapping,3D printed Microchannel,Gold nanoparitcle assembly

Optical trapping, an advanced method utilizing a tightly focused laser beam to confine small objects, offers an opportunity to manipulate materials and explore new emerging microscopic phenomena. In our previous research, we observed a dynamic assembly of gold nanoparticles (Au NPs) occurring only along the glass/solution interface.1 This assembly exhibited directional evolution exclusively perpendicular to the linear polarization of the trapping laser, which we call optical evolved swarming.
In this report, we fabricate microstructures on a glass substrate by melt electrospinning writing (MESW) method, using 3D printing machine (regenHU, 3D Discovery), 2 and apply the substrate as the upper glass of a chamber. A 1064 nm trapping laser is focused from the bottom, inducing optical trapping and swarming of 400 nm Au NPs within 3D-printed polycaprolactone (PCL) structures. The swarming evolves to a dumbbell-shaped morphology where Au NPs fluctuate and migrate as in Fig. 1a. Upon moving the laser focus close to a wall of microchannel, the swarming is deformed to a stable uni-directional morphology (Fig. 1b). When we shift the laser focus onto the microchannel, the swarming disperses but is still stable (Fig. 1d). The PCL structure is damaged, when the swarming is induced near its surface and/or with higher power laser (Fig. 2). This study aims to explore new swarming phenomena about morphology and local heating within the 3D confined space of the fabricated structure.