  In this paper we describe a simple and inexpensive method to generate plasma
using a kitchen microwave. The microwave-generated plasma is characterized by
spectroscopic analysis and compared with the absorption spectra of a gas
discharge tube. A Paschen-like curve is observed leading to a hypothesis of the
microwave plasma generation mechanism in air. We have also demonstrated that
this microwave generated air plasma can be used in a multitude of applications
such as: a) surface modification of a substrate to change its wettability; b)
surface modification to change electrical/optical properties of a substrate;
and c) enhancement of adhesive forces for improved bonding of polymeric
microfluidic molds, such as bonding polydimethylsiloxane (PDMS) chips to glass
covers. These simple techniques of plasma generation and subsequent surface
treatment and modification may lead to new opportunities to conduct research
not only in advanced labs, but also in undergraduate and even high school
research labs.
