Analysis of optimum electro-rotation technique

Abstract

Single-particle rotation is described and illustrated by highlighting the similarities between the rotational spectra of biological particles and the spectra expected of ferroelectric and other inorganic particles such as semiconductors. Possible new applications of this technique in materials science are suggested. It is shown that, for quantitative measurements of a particular parameter, the most useful part of the rotational spectrum is the field frequency (f_c) that gives maximum rotation speed. In many cases this frequency is that of the dielectric dispersion occurring within the particle or particle-medium system. A method for the precise (°2%) measurement of this frequency and the most practical apparatus for implementing this method are described. The use of switched voltages (square waves, pulses) as driving voltages for field excitation is analysed, and it is investigated whether such methods of minimal complexity can achieve the very high accuracy of which the method is capable.