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Laser Technique Builds Micro-Structures
on a Human Hair
Researchers
from Boston College have demonstrated the fabrication
of microscopic polymeric structures on top of a
human hair, without harming it. The researchers
used a technique called multiphoton-absorption photopolymerization
(MAP), in which a polymer can be deposited at the
focal point of a laser beam; scanning of the laser
beam in a desired pattern then allows for the formation
of intricate, three-dimensional patterns. This technique
makes it possible to create features that are 1,000
times smaller than the diameter of a human hair.
These new results show that MAP can be used to fabricate
structures nondestructively on biomaterials, and
point the way towards applications of MAP in the
creation of miniature biodevices, which could include
micromanipulators for cells or even individual protein
or DNA molecules.
The originial purpose of the study was to demonstrate
that intricate and resilient structures could be
created with MAP using inexpensive and readily available
materials. In order to demonstrate the size of the
features that could be created, the researchers
fabricated structures near a human hair, and in
the course of these experiments they discovered
that it was also possible to fabricate structures
on the hair itself.
Three-dimensional structures created with this techniqdfue
also have the potential to be used in other miniature
devices, such as optical communications hardware:
fiber optics and the hardware that is used to interface
them with electronics.
Visit http://chemserv.bc.edu/Department/faculty/fourkas/fourkas.html
Electron microscopy images at increasing
magnification of a representative structure created
on a human hair. The strokes on the letters are
more than 20 times smaller than the diameter of
the hair. (Christopher N. LaFratta)
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