Patent ID: 6991906

Claim:
A procedure to exert or measure optically-induced forces which are capable of moving at least one particle or holding at least one particle in a focus of an optical cage formed with a light beam, comprising: a) positioning the focus in a microelectrode arrangement in which an electrical field is formed that has a field gradient which forms a three-dimensional electrical capture area, said electrical capture area representing an electrical field cage with a capture point at a minimum electrical field level of the capture area, wherein the focus is positioned at a distance from the capture point b) positioning said at least one particle at one of the focus and the capture point, c) varying at least one parameter selected from an amplitude of said electrical field, a light power of said light beam and the distance of the capture point from the focus until the particle moves between the focus and the capture area, and d) exerting said optically-induced forces, wherein said at least one particle is at least temporarily moved between the focus and the capture area, or measuring said optically-induced forces, wherein said at least one parameter varied in step c) is detected when said at least one particle moves between the focus and the capture point.