Lifeboat Foundation

Researchers have developed a number of potassium ion (K⁺) probes to detect fluctuating K⁺ concentrations during a variety of biological processes. However, such probes are not sensitive enough to detect physiological fluctuations in living animals and it is not easy to monitor deep tissues with short-wavelength excitations that are in use so far. In a new report, Jianan Liu and a team of researchers in neuroscience, chemistry, and molecular engineering in China, describe a highly sensitive and selective nanosensor for near infrared (NIR) K⁺ ion imaging in living cells and animals. The team constructed the nanosensor by encapsulating upconversion nanoparticles (UCNPs) and a commercial potassium ion indicator in the hollow cavity of mesoporous silica nanoparticles and coated them with a K⁺ selective filter membrane. The membrane adsorbed K⁺ from the medium and filtered away any interfering cations. In its mechanism of action, UCNPs converted NIR to ultraviolet (UV) light to excite the potassium ion indicator and detect fluctuating potassium ion concentrations in cultured cells and in animal models of disease including mice and zebrafish larvae. The results are now published on Science Advances.

The most abundant intracellular cation potassium (K⁺) is extremely crucial in a variety of biological processes including neural transmission, heartbeat, muscle contraction and kidney function. Variations in the intracellular or extracellular K⁺ concentration (referred herein as [K⁺]) suggest abnormal physiological functions including heart dysfunction, cancer, and diabetes. As a result, researchers are keen to develop effective strategies to monitor the dynamics of [K⁺] fluctuations, specifically with direct optical imaging.

Most existing probes are not sensitive to K⁺ detection under physiological conditions and cannot differentiate fluctuations between [K⁺] and the accompanying sodium ion ([Na⁺]) during transmembrane transport in the Na⁺/K⁺ pumps. While fluorescence lifetime imaging can distinguish K⁺ and Na⁺ in water solution, the method requires specialized instruments. Most K⁺ sensors are also activated with short wavelength light including ultraviolet (UV) or visible light—leading to significant scattering and limited penetration depth when examining living tissues. In contrast, the proposed near-infrared (NIR) imaging technique will offer unique advantages during deep tissue imaging as a plausible alternative.

The era of telecommunications systems designed solely by humans is coming to an end. From here on, artificial intelligence will play a pivotal role in the design and operation of these systems. The reason is simple: rapidly escalating complexity.

Each new generation of communications system strives to improve coverage areas, bit rates, number of users, and power consumption. But at the same time, the engineering challenges grow more difficult. To keep innovating, engineers have to navigate an increasingly tangled web of technological trade-offs made during previous generations.

In telecommunications, a major source of complexity comes from what we’ll call impairments. Impairments include anything that deteriorates or otherwise interferes with a communications system’s ability to deliver information from point A to point B. Radio hardware itself, for example, impairs signals when it sends or receives them by adding noise. The paths, or channels, that signals travel over to reach their destinations also impair signals. This is true for a wired channel, where a nearby electrical line can cause nasty interference. It’s equally true for wireless channels, where, for example, signals bouncing off and around buildings in an urban area create a noisy, distortive environment.

Your phone’s GPS, the Wi-Fi in your house and communications on aircraft are all powered by radio-frequency, or RF, waves, which carry information from a transmitter at one point to a sensor at another. The sensors interpret this information in different ways. For example, a GPS sensor uses the angle at which it receives an RF wave to determine its own relative location. The more precisely it can measure the angle, the more accurately it can determine location.

In a new paper published in Physical Review Letters, University of Arizona engineering and optical sciences researchers, in collaboration with engineers from General Dynamics Mission Systems, demonstrate how a combination of two techniques—radio frequency photonics sensing and quantum metrology—can give sensor networks a previously unheard-of level of precision. The work involves transferring information from electrons to photons, then using quantum entanglement to increase the photons’ sensing capabilities.

“This quantum sensing paradigm could create opportunities to improve GPS systems, astronomy laboratories and biomedical imaging capabilities,” said Zheshen Zhang, assistant professor of materials science and engineering and optical sciences, and principal investigator of the university’s Quantum Information and Materials Group. “It could be used to improve the performance of any application that requires a network of sensors.”

Only 10 years ago, scientists working on what they hoped would open a new frontier of neuromorphic computing could only dream of a device using miniature tools called memristors that would function/operate like real brain synapses.

But now a team at the University of Massachusetts Amherst has discovered, while on their way to better understanding protein nanowires, how to use these biological, electricity conducting filaments to make a neuromorphic memristor, or “memory transistor,” device. It runs extremely efficiently on very low power, as brains do, to carry signals between neurons. Details are in Nature Communications.

As first author Tianda Fu, a Ph.D. candidate in electrical and computer engineering, explains, one of the biggest hurdles to neuromorphic computing, and one that made it seem unreachable, is that most conventional computers operate at over 1 volt, while the brain sends signals called action potentials between neurons at around 80 millivolts—many times lower. Today, a decade after early experiments, memristor voltage has been achieved in the range similar to conventional computer, but getting below that seemed improbable, he adds.

O,.o circa 2007.

Theoretical physicists at the University of St. Andrews have created ‘incredible levitation effects’ by engineering the force of nature which normally causes objects to stick together by quantum force. By reversing this phenomenon, known as ‘Casimir force’, the scientists hope to solve the problem of tiny objects sticking together in existing novel nanomachines.

Professor Ulf Leonhardt and Dr Thomas Philbin of the University’s School of Physics & Astronomy believe that they can engineer the Casimir force of quantum physics to cause an object to repel rather than attract another in a vacuum.

Casimir force (discovered in 1948 and first measured in 1997) can be demonstrated in a gecko’s ability to stick to a surface with just one toe. However, it can cause practical problems in nanotechnology, and ways of preventing tiny objects from sticking to each other is the source of much interest.

Kilopower is a small, light-weight fission nuclear power system capable of providing up to 10 kilowatts of electrical power — enough to run several average households continuously for at least 10 years.

Four Kilopower units would provide enough power to establish an outpost on the Moon or Mars.

#engineering

https://youtube.com/watch?v=fX2tt7etBDw

Here’s another neat thing drones can do—beam power across the sky to recharge sensors in hard-to-reach places.

Remote sensors play a valuable role in collecting data—but recharging these devices while they are scattered over vast and isolated areas can be tedious. A new system is designed to make the charging process easier by using unmanned aerial vehicles (UAVs) to deliver power using radio waves during a flyby. A specialized antenna on the sensor harvests the signals and converts them into electricity. The design is described in a study published 23 March in IEEE Sensors Letters.

Continue reading “Drones Use Radio Waves to Recharge Sensors While in Flight” »

Video Friday is your weekly selection of awesome robotics videos, collected by your Automaton bloggers. We’ll also be posting a weekly calendar of upcoming robotics events for the next few months; here’s what we have so far (send us your events!):

Let us know if you have suggestions for next week, and enjoy today’s videos.

Continue reading “Video Friday: This Free-Flying Robot Head Is Like Alexa for Astronauts” »

Inspired by how human bone and colorful coral reefs adjust mineral deposits in response to their surrounding environments, Johns Hopkins researchers have created a self-adapting material that can change its stiffness in response to the applied force. This advancement can someday open the doors for materials that can self-reinforce to prepare for increased force or stop further damage. A report of the findings was published today in Advanced Materials.

“Imagine a bone implant or a bridge that can self-reinforce where a high force is applied without inspection and maintenance. It will allow safer implants and bridges with minimal complication, cost and downtime,” says Sung Hoon Kang, an assistant professor in the Department of Mechanical Engineering, Hopkins Extreme Materials Institute, and Institute for NanoBioTechnology at The Johns Hopkins University and the study’s senior author.

While other researchers have attempted to create similar synthetic materials before, doing so has been challenging because such materials are difficult and expensive to create, or require active maintenance when they are created and are limited in how much stress they can bear. Having materials with adaptable properties, like those of wood and bone, can provide safer structures, save money and resources, and reduce harmful environmental impact.