Particle guidance system

Abstract

Methods and apparatus are disclosed for using a beam of energy, specifically laser light ( 46 ), to transport, suspend or trap non-atomic size particles ( 59 ) within a hollow-core optical fiber ( 50 ), manipulating the particles ( 59 ) along the fiber ( 50 ) over distances and depositing them on a substrate ( 58 ). A laser generates a beam ( 46 ) focused on a fiber ( 50 ) entrance ( 56 ). A source ( 54 ) delivers particles ( 52 ) to the entrance ( 56 ). Particles ( 52 ) are drawn into the beam ( 46 ) and propelled through the core ( 48 ) of the fiber ( 50 ). Forces (F 1 -F 4 ) on a particle ( 12 ) generated by reflection, absorption and refraction of laser light ( 20 ) keep the particle ( 12 ) close to the fiber's center and propel it along the fiber's length. A variety of micron-size particles, including solids, solid dielectrics, semiconductors, liquids, aerosols and living cells are conveyed. The invention is adapted to direct-writing of micron-sized features ( 66 - 74 ) on surfaces, for example, microcircuits and microcircuit components for “smart” credit cards and biological implants, to recording emission spectra of trapped particles and to many other such uses. Deposited material ( 172 ) is treated by laser light ( 174 ) by particle melting, decomposition, sintering or other chemical and mechanical reactions caused by laser interaction with the particle. Resulting, treated depositions have desirable mechanical and electrical properties for electronics and micro-electronic-mechanical system applications.

What is claimed is:  
     
         1 . A method for depositing material on a substrate comprising the steps of: 
 a. directing a stream of material toward the substrate, wherein the stream is substantially perpendicular to the substrate;    b. applying a laser beam to the substrate, wherein said laser beam is substantially parallel to the stream of material.