Busting dust: From cosmic grains to terrestrial microbes

Electrostatic charging can have important consequences for both the growth and disruption of microparticulates immersed in a plasma. In this topical r eview, my emphasis is on the latter process, while I extend the term microp articulates not only to include ordinary inanimate cosmic or terrestrial du st but also to include terrestrial microbes whose sizes range from tens of nanometers (viruses) to tens of micrometers (bacteria). Following a descrip tion of the basic mechanism of electrostatic disruption of a solid body, I will discuss the role of size, shape and surface irregularity on the proces s. I will also consider the mitigating role of electric field emission of e lectrons on the disruption process of a negatively charged grain as its siz e falls below a critical size. I will conclude by reviewing some early evid ence for the electrostatic disruption of cosmic grains, and the very recent evidence for the electrostatic disruption of the bacterial cell membranes in terrestrial sterilization experiments.