The various challenges and applications of optofluidics have been addressed by the Dean of EPFL School of Enginnering, Demetri Psaltis in the latest issue of Nature Photonics, which focuses on the study of microfluidics with optics.
In the review, Psaltis claims that optofluidics, i.e., the microscopic delivery of fluids through very small tubes and channels, using optics, can be used to develop energy sources.
Psaltis explains that since the efficiency of energy producing systems such as solar cells and biofuel reactors can be increased by directing and concentrating of light, EPFL can develop efficient and disruptive sources of energy by adding another dimension, the precision of micro and nano technology.
By illustrating with an example of an optofluidic solar lighting system, Psaltis explains that by using a light concentrating and distribution system, sunlight that hits the exterior of a building, can be harnessed. The energy can be distributed to the office ceilings, microfluidic air filters and indoor solar panels by using fiber optic cables or light pipes. Since the air filters or solar panels remain in a protective environment, solar energy can be used to supplement the non-renewable resources. In the review, it is explained that deviation from secondary devices such as solar panels and air filtrage is necessary in order to maintain a constant source of light, in the event of a cloud passing over and resulting in the flickering of a light source. Thus, to modulate the various channels, light can be deviated using an electrowetting system. A water droplet is present on the light tube’s outer surface. The ions in the water are excited due to a small current, which pushes the ion to the edge, thus expanding it sufficiently so that it touches the surface of a different tube. The droplet creates a light bridge across the parallel light tubes, thus moderating the quantity of light streaming through them.
A visiting professor at EPFL and a professor at Cornell University, David Erickson stated that the challenge optofluidics in the energy field is maintaining the precision offered by micro and nano light along with fluid manipulation in order to create industrial-sized installations that can fulfill the energy demands of the growing population. Erickson explained that similar to a super computer, which consists of smaller components, the scaling of optofluidic technology will require many liquid chips to be integrated into a super-reactor. The efficiency of such a system would rely on the surface area available for the reactions to occur.
Source: http://sti.epfl.ch/