Presentation Title: Laser-Assisted Micro/Nanoprocessing and Device Fabrication

Abstract: Research on laser-assisted micro and nanoprocessing, nanomachining, nanolithography and nanodeposition is summarized. Fundamental aspects of ultrafast laser coupling with materials are probed by time-of-flight spectroscopy and time-resolved diagnostics. Femtosecond laser radiation enabled writing of 3-D microfluidic channels and hybrid opto-fluidic devices in glass. Pulsed lasers were coupled to near-field-scanning optical microscopes (NSOMs). Experiments have been conducted on the surface modification of metals, polymers and semiconductor materials, including the localized activation of electrical and ferromagnetic domains. Ablation nanolithography and patterning has been demonstrated. NSOM-based ablation is also applied to nanoscale chemical analysis. Interactions of pulsed laser radiation with nanostructures are investigated. Probing of the electronic transport in semiconductor nanowires and nanoparticles has been done with scanning probe photoelectron emission spectroscopy. New concepts are proposed for the high throughput, directed growth and assembly of nanostructures.

New methods are presented for the maskless fabrication of passive and active functional devices on flexible substrates utilizing nanoparticles in conjunction with laser processing and nanoimprinting. Low power, short-pulsed laser ablative material removal enabled finer electrical components to overcome the resolution limitation of inkjet deposition. Temporally modulated laser irradiation was utilized to locally evaporate the carrier solvent as well as sinter gold nano-particles, yielding low resistivity conductors. Selective multi-layered nanoparticle film processing was demonstrated. High-performance nanoelectronics, including OFETs (organic field effect transistors) have been demonstrated on flexible substrates.

Biography: Costas P. Grigoropoulos received his Diploma Degrees in Naval Architecture and Marine Engineering (1978), and in Mechanical Engineering (1980) from the National Technical University of Athens, Greece. He holds a M.Sc. degree (1983), and a Ph.D. (1986), both in Mechanical Engineering from Columbia University. He joined the faculty of the Department of Mechanical Engineering at the University of California at Berkeley in 1990. He holds a faculty staff position with the Environmental Energy Technologies Division at LBNL. His current research interests are in micro/nano engineering, laser materials processing, laser-bio interactions, manufacture of flexible electronics, microscale energy sources, hydrogen storage, microscale and nanoscale transport. His laboratory is engaged in the development of new methods for the manufacture of functional nanoscale devices.