Stephane Marouani, Country Manager ANZ
Building a microscope that sees with helium Shooting small atoms at samples doesn’t damage delicate specimens.
S
from the tip to the sample, generating current and
they have invented a new microscope that takes
a computer image. These microscopes can see
images using neutral helium atoms instead of
individual atoms, a fraction of a nanometre across.
light or electrons.
But all of these methods have drawbacks —
Electron microscopes also require insulating
ometimes, the ‘light’ we need to look
most important, light and electrons can damage a
samples with a conductive layer such as gold,
at something can damage it. That’s the inspiration
sample. Certain materials, such as ice and wax, can
which can obscure the material underneath. The
for a new class of microscope being developed at
melt. Biological samples, such as skin specimens,
photons used in light microscopes can penetrate
the University of Cambridge, England, and the
can suffer structural damage. Electrons pummel
beneath the surface of a sample before reflecting,
University of Newcastle, in Australia.
bacteria biofilms and also organic electronics like
clouding the image of the surface structure.
photovoltaics and transistors.
Helium avoids these challenges. The teams
Scientists already have a plethora of imaging methods. Optical microscopes, which focus light
That’s why the labs of Andrew Jardine, a
have already used the SHeM to image sensitive
through lenses, can resolve features down to about
professor of experimental physics at Cambridge,
biological samples like bio-films and insulators
0.3 µm. Scanning electron microscopes use an
and Paul Dastoor, a professor of physics at
such as PPE fabric.
electron beam to reach a resolution of about 1
Newcastle, are developing a scanning helium
Helium atoms carry much less energy than
nm or better. The highest-resolution microscopes
microscope, or SHeM. Along with their
photons or electrons. They are also electrically
are scanning tunnelling microscopes, in which a
colleagues from the two universities and several
neutral and chemically inert, so in addition to not
sharp tip passes just above the surface of a sample
international collaborators, including those from
battering samples with energy, they won’t interact
and electrons use quantum mechanics to ‘tunnel’
Professor Bodil Holst’s group in Bergin, Norway,
with them electrically or chemically.
22 | LAB+LIFE SCIENTIST - Apr/May 2022
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