Page 50 - Plastics News September 2017

TECHNOLOGY

New device can 'dissolve' waste through water molecules in

atmosphere

team of researchers has come up with a type of onto a fi lm made of the polymer polyanhydride. The
A electronic device that can be triggered to dissolve device remained stable until ambient moisture triggered
through exposure to water molecules in the atmosphere. a chemical breakdown that digested the inorganic
The work from the University of Houston and China holds electronic materials and components. The researchers
promise for eco-friendly disposable personal electronics tested a number of compounds, including aluminum,
and biomedical devices that dissolve within the body. There copper, nickel indium-gallium, zinc oxide and magnesium
are also defense applications, including devices that can oxide, and developed various electronic devices,
be programmed to dissolve in order to safeguard sensitive including resistors, capacitors, antennas, transistors,
information, said lead author Cunjiang Yu. diodes, photo sensors and more, to demonstrate the
model's versatility. The lifespan of the devices can be
controlled by varying the humidity level or by changing
the polymer composition, Yu said.The study is published
in Science Advances.

Liberty IBM system reduces

labor and improves quality

&D/Leverage has fi led for 15 patents in 2017
Rrelated to tooling for injection blow molding. The
result is what the company calls its Liberty IBM system.
The system is designed to solve problems that are
The field, known as physically transient electronics, inherent to the injection blow molding process,
currently requires immersion in aqueous corrosive solutions especially for the start-up of the run, according to
or biofl uids. Yu said this work demonstrates a completely Jeff Chen, director of research & simulation at the
new working mechanism - the dissolution is triggered by Lee's Summit based company.
ambient moisture."More importantly, the transient period The system deals with problems including:
of time can be precisely controlled," he said. • Thermal expansion-related problems like bowing
That means a biomedical implant could be programmed of the die-set.
to disappear when its task - delivering medication, for
• Ability to do “cold starts” without having to torch
example - is complete. Sensitive communications could be
devised to literally vanish once the message was delivered. the nozzles.
And all those old cell phones littering kitchen drawers? New
• Minimizes thermal expansion-induced wear at the
versions could be programmed to dissolve when they are no
nozzle tip and gate area, which also eliminates
longer needed. "We demonstrate that polymeric substrates
frequent replacement of the nozzle.
with novel degradation kinetics and associated transience
chemistry offer a feasible strategy to construct physically • The need to engage and disengaging the manifold
transient electronics," the researchers wrote. "Through the from the injection cavity for startup and
manipulation of the polymer component and environmental shutdown.
humidity, the progress of hydrolyzing polyanhydrides can be
managed and thus the dissolution kinetics of (a) functional • Parting line mismatch.
device can be controlled." The time period can range R&D/Leverage currently has 16 Liberty IBM systems
from days to weeks, or even longer, they said.The model running in the fi eld with cavitation as high as 38
constructed by the researchers works like this: Functional cavities.
electronic components were built via additive processes

Plastics News | September 2017 50