title: Precise selective deposition of microparticles on electrodes of microelectronic chips.
abstract: We examined the high precision deposition of toner and polymer microparticles with a typical size of approximately 10 microm on electrode arrays with electrodes of 100 microm and below using custom-made microelectronic chips. Selective desorption of redundant particles was employed to obtain a given particle pattern from preadsorbed particle layers. Microparticle desorption was regulated by dielectrophoretic attracting forces generated by individual pixel electrodes, tangential detaching forces of an air flow, and adhesion forces on the microchip surface. A theoretical consideration of the acting forces showed that without pixel voltage, the tangential force applied for particle detachment exceeded the particle adhesion force. When the pixel voltage was switched on, however, the sum of attracting forces was larger than the tangential detaching force, which was crucial for desorption efficiency. In our experiments, appropriately large dielectrophoretic forces were achieved by applying high voltages of up to 100 V on the pixel electrodes. In addition, electrode geometries on the chip's surface as well as particle size influenced the desorption quality. We further demonstrated the compatibility of this procedure to complementary metal oxide semiconductor chip technology, which should allow for an easy technical implementation with respect to high-resolution microparticle deposition.
authors: German Cancer Research Center, Im Neuenheimer Feld 580, D-69120 Heidelberg, Germany.
authors: Alexander
authors: A
authors: Nesterov
authors: Kai
authors: K
authors: König
authors: Thomas
authors: T
authors: Felgenhauer
authors: Volker
authors: V
authors: Lindenstruth
authors: Ulrich
authors: U
authors: Trunk
authors: Simon
authors: S
authors: Fernandez
authors: Michael
authors: M
authors: Hausmann
authors: F Ralf
authors: FR
authors: Bischoff
authors: Frank
authors: F
authors: Breitling
authors: Volker
authors: V
authors: Stadler
mesh_terms: D004560:Electricity; D046208:Microchip Analytical Procedures / Q000379:methods*; D008839:Microelectrodes; D010316:Particle Size; D011108:Polymers; D012666:Semiconductors; D013499:Surface Properties
chemical_list: D011108:Polymers