Sep 16, 2002 Microstructures make polymers lase Researchers from
the UK universities of St Andrews and Exeter have made
microstructured polymers using a simple embossing technique. The
team believes this is the first time that the embossing has been
used to make photonic structures in light-emitting polymers
(Applied Physics Letters 81 1955). The approach, known as hot-
embossing, also offers an efficient and simple alternative to
complex fabrication schemes such as photolithography, electron-
beam lithography and chemical etching. To emboss the
microstructures, the researchers press the polymer against a
master pattern and heat it to 200°C. At this temperature, which
is above the polymer's glass transition temperature, the polymer
begins to soften and take-on the pattern of the template.
Cooling allows the polymer to drop below its transition point,
leaving the pattern imprinted on the surface. "The resulting
microstructures have dimensions of 400 nm," says group leader
Ifor Samuel. "And we believe we can make