Fluctuation-Enhanced Sensing: Review of Practical Issues

Abstract

We discuss some of the fundamental practical limitations of the Fluctuation-Enhanced Sensing of odors and gases. We address resolution, measurement speed, reproducibility, memory and other problems such as humidity. Various techniques and ideas are presented to overcome these problems. Circuit solutions are also discussed.

Comparison of forces for the Crookes and Hettner radiometers

“…Clearly, a vane will heat up when exposed to light because of black body absorption of photons. A pressure difference at the surface of the vane drives a net drift of air molecules from the cold side to the warmer side, so the thermal creep force will push each vane in the direction of the net motion of the molecules [9]. Since this force occurs at the edges of the vanes, it can be changed by varying the vane thickness [10].…”