Chemical Engineering Focus Newsletter, Monash University Volume 9, Issue 1 | Page 3

MONASH RESEARCHERS DEVISE
IONIC LIQUID MICROBANDS AS
HIGHLY DURABLE & WEARABLE

BIOMEDICAL SENSORS
“ From our perspective,

stretchable electronics
should be the ultimate
electronic product ”
This February Chemistry World
showcased research led by
Monash University’s Chemical
Engineering’s Professor Wenlong
Cheng. Professor Cheng and his
team of materials scientists and
chemical engineers have developed
a soft and stretchable device that
recognises artery pulses or body
movements, relaying the information
to a smartphone.

device changes while the
voltage remains fixed. A
smartphone is capable of
picking up these variations
in resistance, which are
unique to each movement.
Ionic liquids generally have
lower Young’s moduli than
the elastomeric polymers
typically used in electronic
devices.

Professor Cheng’s work was
originally published in Materials
Horizons (DOI: 10.1039/
C5MH00284B) in a paper titled
“Volume-invariant ionic liquid
microbands as highly durable
wearable biomedical sensors”.
He reports that with the surge in
the demand for wearable devices
with gadgets to monitor body
movements, heart rate and sweat
metabolites, among other things,
many current devices are not truly
wearable as they do not sit flush with
the skin and therefore do not deform
as the body moves.

These low moduli allow the
sensors to bend without
any signs of cracking or
loss of conductivity. While
Professor Cheng has used a model
ionic liquid in this study, his team is
also testing a range of hydrophilic
and hydrophobic ionic liquids for
these sensors.

Professor Cheng used an ionic
liquid sealed in a silicon mould to
counteract these limitations. They
created a durable, waterproof and
lightweight device that senses
body movements. When the sensor
deforms, current running through the

Chemical Engineering

Monash

An ammeter indicates changes in the electric current
running through the sensor as it is stretched © Royal
Society of Chemistry

Professor Cheng foresees a
key application for the sensor in
monitoring health, in particular for
people working at desks on a daily
basis, who may be at risk of cervical
spondylosis – a form of neck pain.
‘From our perspective, stretchable
electronics should be the ultimate
electronic product.’
A/Professor Xiaodong Chen, an
expert in materials science from
Nanyang Technological University
in Singapore, asserts that the

device provides ‘a simple strategy
to monitor the complex motions
of the human body.’ Chemical
engineer Zhenan Bao, from Stanford
University, US, also praises the work,
describing the device as a simple
and elegant approach, with ‘great
potential for applications in wearable
electronics’.
This article originally appeared in Chemistry
World on the 12 February 2016