Optical and acoustic forces for biomedical applications

Moving, stretching or mechanically probing a microscopic sample by exerting controlled forces in a non-contact way is a requirement of many biomedical investigations. Thus optical and acoustic micro-manipulation have both been on the rise in recent years. The differences in the physical laws and in the typical length scales governing acoustic and optical forces make them complementary. While acoustic forces can levitate heavy particles, which optical tweezers cannot not handle without adverse high-power effects, optical forces cover smaller scales down to sub-cellular structures. The specialities of either manipulation modalities and the resulting accessible range of applications will be discussed.