Bonnie Gray, professor at Simon Fraser University.

Editors’ Choice—Development of Screen-Printed Flexible Multi-Level Microfluidic Devices with Integrated Conductive Nanocomposite Polymer Electrodes on Textiles

Bonnie Gray, a professor at Simon Fraser University’s school of engineering science, was inspired by the city of Vancouver in British Columbia in her latest work.

“Vancouver is well-known for its technical clothing, and I have a lot of friends in the film industry who work in costume design. A combination of these influences and my own engineering background caused me to look further into integrating clothing with technology. That’s how I went on to become involved in developing screen-printed flexible multi-level microfluidic devices on textiles,” said Gray, which led to the fruition of her and lead author Daehan Chung‘s research paper, “Development of Screen-Printed Flexible Multi-Level Microfluidic Devices with Integrated Conductive Nanocomposite Polymer Electrodes on Textiles.”

In their open access paper, published in the Journal of The Electrochemical Society, the pair “present a flexible plastisol-based microfluidic process integrated with conductive nanoparticle composite polymer (C-NCP) electrodes for flexible active microfluidic devices on textile substrates.”

According to Gray, flexible and wearable microfluidic devices are among the newest wearable devices for applications in health monitoring, drug delivery systems, and bio-signal sensing. (more…)

JSS Editors’ Choice article discusses AlGaN/GaN HEMTs

Image: “On the Radiation Tolerance of AlGaN/GaN HEMTs“

When it comes to putting technology in space, size and mass are prime considerations. High-power gallium nitride-based high electron mobility transistors (HEMTs) are appealing in this regard because they have the potential to replace bulkier, less efficient transistors, and are also more tolerant of the harsh radiation environment of space. Compared to similar aluminum gallium arsenide/gallium arsenide HEMTs, the gallium nitride-based HEMTs are ten times more tolerant of radiation-induced displacement damage.

Until recently, scientists could only guess why this phenomena occurred: Was the gallium nitride material system itself so inherently disordered that adding more defects had scant effect? Or did the strong binding of gallium and nitrogen atoms to their lattice sites render the atoms more difficult to displace?

The answer, according to scientists at the Naval Research Laboratory, is none of the above.

Examining radiation response

In a recent open access article published in the ECS Journal of Solid State Science and Technology entitled, “On the Radiation Tolerance of AlGaN/GaN HEMTs,” the team of researchers from NRL state that by studying the effect of proton irradiation on gallium nitride-based HEMTs with a wide range of initial threading dislocation defectiveness, they found that the pre-irradiation material quality had no effect on radiation response.

Additionally, the team discovered that the order-of-magnitude difference in radiation tolerance between gallium arsenide- and gallium nitride-based HEMTs is much too large to be explained by differences in binding energy. Instead, they noticed that radiation-induced disorder causes the carrier mobility to decrease and the scattering rate to increase as expected, but the carrier concentration remains significantly less affected than it should be.

(more…)

Research highlighting transformative scientific discoveries

ECS published its first Editors’ Choice article on Tuesday, March 22, 2016 in the Journal of The Electrochemical Society. The article, entitled “Communication—Comparison of Nanoscale Focused Ion Beam and Electrochemical Lithiation in β-Sn Microspheres,” details transformative findings in the dosage and spatial distribution of lithiation.

Editors’ Choice articles are a special designation of ECS’s newly established Communication articles, which are designed to highlight breakthrough preliminary research and bolster the scientific discovery process. ECS journal editors designate exemplary Communication articles as Editors’ Choice when the research presented is transformative, detailing either novel advancements in a field or completely new discoveries.

“This paper introduces the use of a focused Li-ion beam (Li-FIB) as a new tool that is designed to probe lithiation mechanism at the nanoscale,” says Nick Wu, Associate Editor of the Journal of The Electrochemical Society. “This technique, which employs a focused Li-ion beam with spot size of a few tens of nanometers and kinetic energy of a few keV, enables precise dosage and spatial distribution of lithiation.”

Papers chosen as Editors’ Choice are regarded as having the highest quality, impact, significance, and scientific or technological interest to electrochemical and solid state science and technology. In order to disseminate these findings to the scientific community at large and open the door to faster developments of practical applications, all Editors’ Choice articles are published Open Access.

“Furthermore,” Wu says, “lithiation in this technique is carried out in the absence of electrolytes so that it allows the study of lithiation dynamics solely in the bulk or surface layers (coatings) of the electrode material without the confounding influences from the electrolyte interactions.”

Each paper undergoes the same rigorous peer-review process associated with ECS journals, with Editors’ Choice articles showing extraordinary direction, concept, interpretation, field, or way of doing something.

Read the full Open Access paper in the ECS Digital Library: http://jes.ecsdl.org/content/163/6/A1010.full.