A conventional microwave oven uses an antenna to squirt microwaves
into a reflective box where they preferentially excite and heat anything
rich in water molecules. A new experiment performed in the group of
Michael Golosovsky and Dan Davidov at the Racah Institute of Physics,
the Hebrew University of Jerusalem reduces the antenna size and dispenses
with the resonant box and, by getting really close to the sample of
soft matter, can heat a tiny spot, one half by one quarter of a millimeter
in size, up to temperatures of 120 C (or 250 F).
One possible application would be "tissue welding," the process of
binding together edges of cut tissue using "biological solder" such
as albumin. Infrared lasers can do such welding, but Golosovsky (golos@vms.huji.ac.il,
972-2658-6551) says that the microwave approach uses much lower power,
can do the job faster, can deposit radiation at deeper levels in the
wound, and bandages are transparent to the microwaves. Also collateral
tissue damage would be better controlled. (Copty
et al., Applied Physics Letters, 21 June 2004.)
