fluid transistor

EFT

		Electronic Fluid Transistor (EFT) -- In 1984 Cytonix, developed the Fluid Transistor™ for conventional and digital micro-manipulation of chemical & biological fluids by optically or electromagnetically controlling the surface energy of hydrophobic surfaces using electrodes and optics. ElectroWetting was used on a microscopic scale to load channels and reservoirs, direct the flow of fluids and move packets of liquid along directed paths. This work became largely public domain after publication of the 1987-88 National Science Foundation sponsored SBIR Phases I and II investigations. Since that time, Cytonix has been actively engaged in the development of hydrophobic, oleophobic and super hydrophobic materials, miniaturized fluidic technologies, and new, proprietary methods of digital fluid control. The 1997 Cytonix US Patent 6143496 (pages 2, 3, 11, 12,15, 18, 19, 20, 26 and 30) and pending US Continuation Application 20080169184 (pages 2, 3, 4 and 6) described devices having a fluid "affinity" being induced in a portion or mass array of portions of a surface by optical, electronic, magnetic or electromagnetic means and causing surface charge to increase the effective surface tension and wettability. The affinity could be reshaped or relocated for the purpose of moving, enlarging, dividing or joining fluids in an assembly. Hydrophobic surfaces could be made wettable using electormagnetic, photonic or electrostatic forces provided by internal or external electrodes comprising Indium oxide or other conductive materials to form a region or spot which can be charged to form an attractive force.
		FluoroPel™ PFC 1601V, PFC 1101V and M1601V, developed at Cytonix for ElectroWetting and extreme enviromental applications, are chosen world wide for low surface energy, minimal contact angle hysteresis and UV breakdown resistance. M1604V iand M1608V are superhydrophobic materials, exibiting contact angels of greater than 175° to water., as documented by DARPA. FluoroPel PFC 1601V and 1101V are favored materials for ElectroWetting sign and display technology. "For reasons that are still under investigation, only a limited set of surfaces exhibit the theoretically predicted electrowetting behavior. Amorphous fluoropolymers are the best electrowetting materials discovered so far, and it has been found that their behaviour can be enhanced by the appropriate patterning. Three types of such polymers are commercially available: FluoroPel hydrophobic and superhydrophobic V-series polymers are sold by Cytonix, CYTOP is sold by Asahi Glass Co., and Teflon AF is sold by DuPont." (Wikipedia Electrowetting Materials)
		Beginning in 1984, Cytonix was first to use: hydrophobic, oleophobic and superhydrophobic coatings with dielectric sub-layers on metal and ITO electrowetting electrodes; arrangements of matched, saw-tooth or offset upper and lower electrode elements, interleaved single-side control elements, and micro-electrode elements on one side with a large plane electrode on the other side; DC or RF control voltages; and step-by-step, microelectrode-to-microelectrode digital drop manipulation. These concepts were expressed in research under NSF Phase I and Phase II SBIR Grants in 1987-1989 and made public in 1990. Saw toothed or interleaved adjacent electrodes allowed drops to be in contact with "hot" electrodes as well as adjacent electrodes at the same time, promoting smooth, uninterrupted, step-wise motion of micro drops along selected paths. FluoroPel PFC M1600V, 1600V and 1100V solutions have played a significant part in past and current developments of the Fluid Transistor and Digital Microfluidics.
		Currently at the forefront in commercializing electrowetting-based applications based in part on Cytonix research: signs and displays by the Novel Devices Laboratory at the University of Cincinnati; clinical diagnostics by Advanced Liquid Logic which was spun out of Duke University; electronic paper by LiquaVista, which was spun out of Philips Research; liquid lenses by Varioptic; and Digital PCR by Life Technologies and Sequenom.
		Cytonix initiatives are presently in Nano Activating Elements, Digital Micro Fluidics, Electrowetting materials and methods, Opto Electric Wetting, and random access high density addressable and configurable fluidic mass arrays.

DigitalPCR is now a trademark of Life Technologies (1995-2009). Fluid Transistor and FluoroPel are trademarks of Cytonix (1984-2009)