25 April 2020 / www.theengineer.co.uk
devices could, said Hague, form the basis of
future sensors for detecting changes in
temperature or even the presence of pathogens
such as viruses.
Another promising application is in-situ
polymerisation, where droplets of monomer
and catalyst are jetted, collided together and
polymerised on the substrate. Hague said this
approach could be used to create polymers with
a higher molecular weight (often desirable from
an engineering point of view) than other
additive polymers.
The team is also exploring the area of
metal-jetting, which is something of a holy grail
for additive researchers around the world. Here,
it is using the so-called MetalJet machine, an
experimental system developed by inkjet
specialist Oce (part of Canon), that is able to jet
individual droplets of different metals at
temperatures of up to 2000 degrees C.
Hague said that whilst ultimately such
systems open the possibility for printing entire
electronic components, the research is
currently focused on the fundamentals of
fusing materials together, and the impact that a
host of different parameters – such as
temperature, droplet velocity and droplet size
can have on this process. “At the moment we’re
not interested in making shapes, we’re much
more interested in understanding how you jet a
range of different materials and how you
interface those different materials,” he said.
Alongside the fundamentals of the
techniques, another key area for the group is in
materials development and analysis. There are,
explained Hague, a relatively small number of
materials available for additive manufacturing,
and expanding the range of materials is a key
priority if the technology is to fulfil its potential.
A key capability here is an automated pick
and place pipetting system, adapted from
technology used in the pharmaceutical industry,
that the team is using to screen new materials
for jetting.
Analysing the rheology, surface tension and
viscosity of new materials to see whether they
are suitable for jetting is a time-consuming
process that can take up to three hours for just a
single material, explained Hague. The new
system has turbocharged this process, enabling
the team to test around 96 materials in just a
couple of hours. “It’s like chucking a bunch of
material at a wall and seeing which ones stick,”
he said. “We’re taking a broad-brush approach
for materials screening so we can determine
whether we think something’s in the printable
range.”
He added that the group is now looking at
whether similar techniques could be applied to
other liquid polymer systems, and even
potentially metals.
The centre’s ability to target so many
different research areas is thanks, in no small
part, to its diverse and cross-disciplinary nature.
Hague self-deprecatingly refers to himself as the
“lowly mechanical engineer” in a team of
physicists, material scientists, chemists and
other specialists. Where necessary, the team is
also able to draw on the wider expertise
available elsewhere in the university as well as
externally. “We’re a big group, with broad
capability but we like to collaborate,” said
Hague.
This cross-disciplinarity is particularly
evident through the centre’s work in the
healthcare and pharmaceutical sectors, a
rapidly growing area of research which is seeing
it work alongside some of the biggest names in
pharma (Astrazenaca, Pfizer, and GSK to name
just a few) on the applications of AM to
technologies including tailored
pharmaceuticals, electroceuticals and
biosensors.
For Hague, who began his academic career
firmly focused on the industrial applications of
additive technologies, this ever-widening range
of application areas fuels an infectious
enthusiasm for an area of technology that
continues to shape our world in unexpected and
fascinating ways. “My job enables me to see
things that most people only dream of seeing. It
gives me access to industry and research that I
never thought a boy from Suffolk would get to
work in! It’s a bit of a dream, if you’re a tinkerer,
like I am, it’s an absolute privilege”
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