1. Optical trapping and integration of semiconductor nanowire assemblies in water Peter J. Pauzauskie, Aleksandra Radenovic, Eliane Trepagnier, Hari Shroff, Peidong Yang and Jan Liphardt Nature Materials, Feb. 2006, Vol. 5

2. Optical Tweezers Principles Rayleigh Limit Particle size << λ Particle treated as a dipole in inhomogenous E-field Mie Limit Particle size >> λ Particles refract the light → Change of momentum → Equal and opposite momentum D.G. Grier, Nature 2003

3. Trapping Procedure

4. Trapping of a SnO 2 Nanoribbon Laser Spot Nanoribbon

5. Applications: 1. Construction of Heterosructures GaN nanowire laser-fused To SnO 2 nanoribbon Construction of 3-dimensional structures Gold droplets generated from coverslip

6. Applications: 2. Others GaN non-specifically attached to HeLa cell membrane Excitation of fluorescent beads Bead Touching The nanoribbon Bead 500nm away from nanoribbon

7. Scanning of GaN nanowire on HeLa Cell

8. Summary Advantages –Trapping of single nanowires of different material with diameters as small as 10 nm –Three dimensional assembly of nanowires Limitations –Difficulty in trapping metallic nanowires –Small working area (100 μm×100 μm) –Large optical power density (10 7 W/cm 2 )