Optofluidic sensing and actuation with optical tweezers

The optical tweezers effect offers the potential for all-optical control of microfluidic and optofluidic devices. Several possible means for applying optical tweezers to optofluidics are described including the use of polymers to tether transversely trapped microspheres and eliminate the need for axial trapping. Also covered is the use of optically trapped cantilevers to make durable devices and to allow the optically actuated elements to be integrated into the devices during manufacture. Self-aligning fibre-optic confocal detection of backscattered light is used to measure the position of the trapped object with respect to the axis of the trap for application to force sensing.