Medical Design Briefs - June 2022 - 22

n Micro-CAL Process Prints
Fine Features in Glass
Microstructures
n Folding Design Leads
to Heart Sensor with
Smaller Profile
3D printed glass lattices, displayed
in front of a U.S. penny for
scale. (Credit: Joseph Toombs)
Researchers have developed
a new way to 3D print glass microstructures
that is faster and
produces objects with higher
optical quality, design flexibility,
and strength. They expanded
the capabilities of computed axial lithography (CAL) to
print much finer features and to print in glass. They dubbed
this new system " micro-CAL. "
Glass is the preferred material for creating complex microscopic
objects, including lenses in endoscopes, as well as
micro fluidic devices used to analyze or process minute
amounts of liquid. To print the glass, the team collaborated
with scientists who have developed a special resin material
containing nanoparticles of glass surrounded by a lightsensitive
binder liquid. Digital light projections from the
printer solidify the binder, then the researchers heat the
printed object to remove the binder and fuse the particles
together into a solid object of pure glass.
The CAL 3D printing method offers manufacturers of microscopic
glass objects a new and more efficient way to meet customers'
demanding requirements for geometry, size, and optical
and mechanical properties. Specifically, this includes
manufacturers of microscopic optical components.
For more information, visit www.medicaldesignbriefs.com/roundup/
0622/glass.
n Nanomaterial Improves
Insulin's Effects
Researchers have developed
a compound consisting
of insulin bound to a string of
amino acids that includes an
antioxidant group. An earlier
A nanomaterial may improve insulin's
effects on the nervous system.
(Credit: Shutterstock)
study in mice suggested this
nanomaterial's anti-diabetes
properties included improving
glucose consumption and
availability as fuel for the brain.
The scientists used a molecule called AAC2 to bind to insulin's
chemical structure. They created a series of molecules
out of small chains of amino acids and, to make AAC2, the
addition of a structural fragment of the antioxidant coumarin.
The chains are designed to stack like bricks and stick to
each other in a way that enables them to self-assemble into
nanofibers that carry a positive electrical charge. The electrical
forces hold insulin and AAC2 together to form a supramolecular
complex.
The team found that only the combination therapy produced
steady glucose levels in the mice over a long period of
time and positively influenced gene expression and neurotransmitter
transport in their brains. The mice treated with
the combination therapy also performed better on cognitive
behavioral tests than animals treated with only insulin or the
nanofiber AAC2.
For more information, visit www.medicaldesignbriefs.com/roundup/
0622/nanomaterial.
22
Cov
MDB RD Roundup 0622_1.indd 22
The semiconductor sensor that detects
antigen molecules by capturing
them on the surface of a
nanosheet film. (Credit: Toyohashi
University of Technology)
Wireless, wearable, and flexible
electrocardiogram monitor
with app data. (Credit:
Kuniharu Takei)
As advances in wearable devices
push the amount of information
they can provide consumers, sensors
increasingly must conform to the
contours of the body. One approach
applies the principles of kirigami to
give sensors the added flexibility.
The sensor uses cuts in a film made of polyethylene terephthalate
(PET) printed with silver electrodes to fit on a person's
chest to monitor his or her heart. In terms of wearability, by applying
kirigami structure in a PET film, due to PET deformation
and bending, the film can be stretchable, so that the film can
follow skin and body movement like a bandage. Such a technique
allows relatively stiff materials, like PET, to adapt to their
surfaces.
The team found that the optimal size of the sensor is roughly
200 sq mm with a distance of 1.5 cm between electrodes. At that
size, they were able to detect enough signal from the heart to
be used in a smartphone app. The device with the sensor could
accurately and reliably relay heart data across multiple people
doing many types of everyday movements, such as walking or
working while seated in a chair.
For more information, visit www.medicaldesignbriefs.com/roundup/
0622/sensor.
n Microchip Detects
Prostate Cancer Markers
Measuring devices that perform
disease tests simply and
quickly from small amounts of
blood, urine, saliva, and other
bodily fluids are extremely important
for accurate diagnosis
and verifying the effectiveness
of therapeutic treatments. PSA
is a marker that increases in the blood as a result of prostate cancer.
Marker screening of saliva is also carried out as a less-invasive form
of cancer risk testing. A microscale testing chip that uses flexibly
deforming nanosheets is formed using semiconductor micromachine
technology to determine the presence or absence of disease.
The research team changed the materials used from the conventional
method, and instead adopted a method of depositing
the functional layer by chemical vapor deposition. As a result, a
thinner, more uniform, and less-degraded sensor chip was created.
Using the biosensors developed on this occasion, the
team conducted an experiment detecting prostate cancer biomarkers,
and succeeded in detecting 100 attograms molar concentration
contained in one milliliter of fluid.
This lower limit detection concentration is comparable to
that of large testing devices using labeling agents and can be
hoped to be applied in ultrasensitive testing with portable-scale
testing devices. Furthermore, since it is possible to detect how
nanosheets deform by adsorption of molecules in real time, it
is possible to detect disease-derived molecules faster than in
comparison with testing equipment using labeling agents.
For more information, visit www.medicaldesignbriefs.com/roundup/
0622/microchip.
www.medicaldesignbriefs.com
ToC
5/25/22 2:49 PM
Medical Design Briefs, June 2022
http://www.medicaldesignbriefs.com/roundup/0622/sensor http://www.medicaldesignbriefs.com/roundup/0622/glass http://www.medicaldesignbriefs.com/roundup/0622/nanomaterial http://www.medicaldesignbriefs.com/roundup/0622/microchip http://www.medicaldesignbriefs.com
Medical Design Briefs - June 2022

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