Faraday Discussions 137 This volume focuses on micron sized particles, with emphasis on particles spanning a size range of 100 nm to 100 ?m, dispersed in a gaseous or liquid medium. The role of microparticles in complex environments is poorly understood and techniques to study the chemical and physical dynamics of microparticles are continually developing. Researchers can now characterise the size, composition and morphology of microparticles and trap and manipulate single particles. Work is presented in the following areas: Optical spectroscopy of microparticles; elastic scattering, Raman scattering, fluorescence spectroscopy, non-linear spectroscopy Chemical dynamics of microparticles; including chemistry relevant to the atmosphere, soft condensed matter, dusty plasmas, combustion processes Physical dynamics of microparticles; including phase transformation, size morphology, interparticle interactions New techniques for manipulating and characterising microparticles; optical and electrodynamic methods, new analytical techniques