Generation of optofluidic microchannels in ice

We demonstrate that light can be used to create microchannels in ice. We make use of free space and fiber coupled infrared laser light to produce microchannels with diameters down to 100 microns in diameter. We demonstrate that the channels can be created in a timescale of seconds and that by controlling the input power that they can be stabilized over a timescale of several minutes using powers as low as 30mW. We compare the fiber coupled geometry, using both single mode and multimode fiber and free space coupling and show that fiber coupling produces optimal results. We demonstrate that liquid samples can be inserted into the channels and particle movement is observed using a combination of optical and thermally induced forces. We also present data looking at droplet freezing within the microchannels. We present preliminary results looking at dual beam coupling into such optofluidic channels and examine prospects for using such channels as rapid microfluidic prototypes. We further discuss the possibility of using optically shaped ice channels as a means to study aerosol nucleation processes and the ability of ice to act as a template for microfluidic devices.