Single-Fiber Optical Tweezers for Cellular Micro-Manipulation

Researchers at the University of California, Irvine, US, have developed single-fiber optical tweezers for cellular micro-manipulation that demonstrated in-depth single fiber optical trapping of low- and high-index particles using micro-axicon-tip fibers. It was also demonstrated that the shape of the cone angle at the axicon's tip enabled fiber-optic trapping in the near-field. Researchers also demonstrated controlled guidance of neuronal growth, along with trapping and stretching of neurons using fiber-optic tweezers. It was also demonstrated that the cells can be stretched by the combined action of forces, such as an attractive gradient force due to fiber-optic tweezers at beam power pulling the membrane and a scattering force on the membrane. Alignment of intracellular dark material along the direction of laser beam propagation was also observed during the demonstrations.