Bacteria
have potential for manufacturing a wide range of materials, but they also play
host to viruses called bacteriophages. The M13 bacteriophage is one such
species which propagates rapidly inside an infected bacteria.
The
M13 phage is a small rod shape virus (880nm x 6.6nm) and when concentrated, the
rods line up to form liquid crystals with a structure reminiscent of corn in a
cornfield.
With
a little bit of protein modification, Lee et
al have formed these into stable multilayers on a gold surface (1). They
then made a sandwich of the M13 phage film with another gold surface. After a
bit of soldering and embedding the sandwich in a Silicone rubber block they had a
tiny device that generated a voltage when squeezed.
The
viral film is piezoelectric, so more squeezing gives more output, sufficient to
turn on a liquid crystal display. This took a multilayer of twenty units covering
an area of around the size of a key on your computer keyboard. Maybe one day
soon we’ll be typing using virus power.
