Magnetic Fields To Remotely Control Body Movements

Scientists have used magnetism to activate tiny groups of cells in the brain, inducing bodily movements that include running, rotating and losing control of the extremities — an achievement that could lead to advances in studying and treating neurological disease. The technique researchers developed is called magneto-thermal stimulation. It gives neuroscientists a powerful new tool: a remote, minimally invasive way to trigger activity deep inside the brain, turning specific cells on and off to study how these changes affect physiology.

Magnetic nanoparticles stimulate neurons deep in the brain to evoke body movements of mice. This image shows a section of a mouse brain with injected magnetic nanoparticles (colored red) covering targeted cells in the striatum

There is a lot of work being done now to map the neuronal circuits that control behavior and emotions,” says lead researcher Arnd Pralle, PhD, a professor of physics in the University at Buffalo College of Arts and Sciences. “How is the computer of our mind working? The technique we have developed could aid this effort greatly.”

Understanding how the brain works — how different parts of the organ communicate with one another and control behavior — is key to developing therapies for diseases that involve the injury or malfunction of specific sets of neurons. Traumatic brain injuries, Parkinson’s disease, dystonia and peripheral paralysis all fall into this category.

The advances reported by Pralle’s team could also aid scientists seeking to treat ailments such as depression and epilepsy directly through brain stimulation.


SuperPowerful Tiny Device Converts Light Into Electricity

In today’s increasingly powerful electronics, tiny materials are a must as manufacturers seek to increase performance without adding bulk. Smaller also is better for optoelectronic devices — like camera sensors or solar cells —which collect light and convert it to electrical energy. Think, for example, about reducing the size and weight of a series of solar panels, producing a higher-quality photo in low lighting conditions, or even transmitting data more quickly.

However, two major challenges have stood in the way: First, shrinking the size of conventionally used “amorphousthin-film materials also reduces their quality. And second, when ultrathin materials become too thin, they are almost transparent — and actually lose some ability to gather or absorb light.

Now, in a nanoscale photodetector that combines both a unique fabrication method and light-trapping structures, a team of engineers from the University at Buffalo (UB) and the University of Wisconsin-Madison (UW-Madison) has overcome both of those obstacles. The researchers — electrical engineers Qiaoqiang Gan at UB, and Zhenqiang (Jack) Ma and Zongfu Yu at UW-Madison — described their device, a single-crystalline germanium nanomembrane photodetector on a nanocavity substrate, in the July 7, 2017, issue of the journal Science Advances.

This image shows the different layers of the nanoscale photodetector, including germanium (red) in between layers of gold or aluminum (yellow) and aluminum oxide (purple). The bottom layer is a silver substrate

We’ve created an exceptionally small and extraordinarily powerful device that converts light into energy,” says Gan, associate professor of electrical engineering in UB’s School of Engineering and Applied Sciences, and one of the paper’s lead authors. “The potential applications are exciting because it could be used to produce everything from more efficient solar panels to more powerful optical fibers.”

The idea, basically, is you want to use a very thin material to realize the same function of devices in which you need to use a very thick material,” says Ma, the Lynn H. Matthias Professor and Vilas Distinguished Achievement Professor in electrical and computer engineering at UW-Madison, also a lead author. Nanocavities are made up of an orderly series of tiny, interconnected molecules that essentially reflect, or circulate, light.

The new device is an advancement of Gan’s work developing nanocavities that increase the amount of light that thin semiconducting materials like germanium can absorb. It consists of nanocavities sandwiched between a top layer of ultrathin single-crystal germanium and a bottom, reflecting layer of silver.


300 Colors Rainbow Polymer May Detect Disease

University at Buffalo (UB) engineers have developed a one-step, low-cost method to fabricate a polymer with extraordinary properties: When viewed from a single perspective, the polymer is rainbow-colored, reflecting many different wavelengths of light.
Used as a filter for light, this material could form the basis of handheld multispectral imaging devices that identify the “true color” of objects examined.
Such portable technology could have applications in a wide range of fields, from home improvement, like matching paint colors, to biomedical imaging, including analyzing colors in medical images to detect disease,” said UB Vice President for Research and Economic Development Alexander N. Cartwright, one of the UB researchers who led the study.
The ease of producing the polymer could make it feasible to develop small devices that connect with cell phones to conduct multispectral imaging, said Qiaoqiang Gan, a UB assistant professor of electrical engineering and another member of the research team.
rainbowA rainbow-colored grating, about 25 millimeters wide, under sunlight. Enlarged microscope images show the graded surface, with the black bars indicating a length of 10 micron

Our method is pretty low-cost, and because of this and the potential cell phone applications, we feel there is a huge market for improving clinical imaging in developing countries,” Gan said.
Because the colors of the rainbow filter are produced as a result of the filter’s surface geometry, and not by some kind of pigment, the colors won’t fade over time. (It’s the same principle that gives color to the wings of butterflies and feather of peacocks.)
Cartwright and Gan’s team reported on their polymer fabrication technique online in Advanced Materials.

How To Protect Laptops From Heat Generation

As smartphones, tablets and other gadgets become smaller and more sophisticated, the heat they generate while in use increases. This is a growing problem because it can cause the electronics inside the gadgets to fail. Conventional wisdom suggests the solution is to keep the guts of these gadgets cool. But a new University at Buffalo research paper hints at the opposite: that is, to make laptops and other portable electronic devices more robust, more heat might be the answer.
electric current in a narrow channel

Electric current in a narrow channel

We’ve found that it’s possible to protect nanoelectronic devices from the heat they generate in a way that preserves how these devices function,” said Jonathan Bird, UB professor of electrical engineering. “This will hopefully allow us to continue developing more powerful smartphones, tablets and other devices without having a fundamental meltdown in their operation due to overheating.”
The paper, “Formation of a protected sub-band for conduction in quantum point contacts under extreme biasing,” was published Jan. 19 in the journal Nature Nanotechnology. It is available at the following link: