David Goggins
Former Navy Seal
Career Development
Bryan Cranston
Critical Thinking
Liv Boeree
International Poker Champion
Emotional Intelligence
Amaryllis Fox
Former CIA Clandestine Operative
Chris Hadfield
Retired Canadian Astronaut & Author
from the world's big
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This Kickstarter-funded brass stylus helps you avoid germs in public places

Stop touching doorknobs, elevator buttons, and touch-screens.

  • The CDC says your hands spread germs on objects like tables, ATM machines, elevator buttons, and door handles.
  • Hygiene Hand is a tool to help avoid direct contact with shared surfaces.
  • After a successful funding round on Kickstarter, the Hygiene Hand is now available to everyone.
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New bandages turn color to identify an infected wound

Smart bandages quickly identify antibiotic-resistant bacteria, and normal bacteria, in owies.

Image source: Di Studio/Shutterstock/Big Think
  • Judicious use of drugs for resistant bacteria requires time- and money-consuming tests until now.
  • New smart bandages turn red for resistant bacteria and yellow for antibiotic-sensitive bacteria.
  • The bandages also promote healing with the application of UV light.

The growing incidence of antibiotic-resistant bacteria was already a worrying problem before we all started washing our hands with anti-bacterial soaps in response to SARS-CoV-2. While necessary, we may also have provided even more bacteria the opportunity to develop resistance. Such uncooperative bacteria can often be treated, but before they can, they have to first be identified as antibiotic-resistant — each time the precious meds capable of defeating such bacteria are deployed, we risk bacteria developing resistance to them. This would obviously render them useless, and so they're administered only sparingly to bacteria that have tested as resistant. This testing takes time, and can be expensive.

Researchers at the Chinese Academy of Sciences, Changchun, Jilin province have a better idea: smart bandages that change color to indicate the nature of bacteria they cover. The study describing their research his published in ACS Central Science.

The idea behind the bandages

colored liquids being poured into beaker

Image source: Alex Kondratiev/Unsplash

The smart coverings work by leveraging the chemistry of bacterial infections. Integrated into each covering is a metal organic framework (MOF), a structure that allows scientists to embed a few key chemicals in the bandages.

The bandages contain a chemical called nitrocefin that breaks down in the presence of the enzyme β-lactamase — β-lactamase is the enzyme that resistant bacteria produce and use to neutralize antibiotics. It's essentially the chemical source of antibiotic resistance. When the nitrocefin interacts with β-lactamase, it breaks down and turns red — as does the bandage— signifying the presence of an antibiotic-resistant bacteria.

For detecting normal, antibiotic-sensitive bacteria, the bandages leverage the fact that a bacterial infection on your skin causes a reduction in its pH, making the skin more acidic. Each smart bandage contains a chemical called bromophenol blue, and when it encounters a more acidic environment, it turns yellow. Thus, when a smart bandage turns yellow, it's telling you that bacteria is present, but that it's antibiotic-sensitive.

If there's no infection, the covering remains its original green color.

Tests and cures

fluorescent light above mirror

Image source: Khamkhlai Thanet/Shutterstock

The bandages have so far been tested on mice who were infected with one of two different strains of E. Coli bacteria, one antibiotic-sensitive, and one antibiotic-resistant. The smart coverings over the mice's wounds behaved as designed, turning the hoped-for colors over the course of a day or two. After some tweaking, that time — and the identification of bacteria — was reduced to just 2-4 hours.

An additional feature is that the design of their MOF causes UV light shined on them to produce reactive oxygen species (ROS) that puncture the protective membranes surrounding the bacterial cells. This restores their susceptibility to standard antibiotics, meaning that the bandages are both diagnostic and curative.

Given the construction simplicity of the bandages, the researchers are hopeful that they can be easily manufactured at scale to join the fight against antibiotic-resistant bacteria, which is currently credited with 700,000 deaths annually.

Being able to quickly identify resistant bacteria can help prolong the effectiveness of available treatments. As the study puts it, "Because of the "auto-obsolescence" of antibacterial treatments, it is an important issue in the current antibacterial field how to rationally use of existing antibiotics and overcome tolerance."

A new device generates energy from shadows

By leveraging the difference between lit and shadowed areas, a new energy source perfect for wearables is invented.

Image source: Mark Adriane/Unsplash
  • Mobile devices used both indoors and out may benefit from a new energy collection system that thrives on mixed and changing lighting conditions.
  • Inexpensive new collection cells are said to be twice as efficient as commercial solar cells.
  • The system's "shadow effect" would also maker it useful as a sensor for tracking traffic.

For all of its promise, solar energy depends on the capture of light, and the more the better. For residents of sunny climes, that's great, with rooftop collection panels, and solar farms built by utilities in wide open, sunny spaces that can provide power to the rest of us. Now, though, a team of scientists at the National University of Singapore (NUS) has announced success at deriving energy from…shadows.

We've got plenty of them everywhere. "Shadows are omnipresent, and we often take them for granted," says research team leader Tan Swee Ching, who notes how shadows are usually anathema for energy collection. "In conventional photovoltaic or optoelectronic applications where a steady source of light is used to power devices, the presence of shadows is undesirable, since it degrades the performance of devices." His team has come up with something quite different, and Tan claims of their shadow-effect energy generator (SEG) that, "This novel concept of harvesting energy in the presence of shadows is unprecedented."

The research is published in the journal Energy & Environmental Science.

How it works

Image source: Royal Society of Chemistry/NUS

The energy produced by the SEG is generated from the differential between shadowed and lit areas. "In this work," says Tan. "We capitalized on the illumination contrast caused by shadows as an indirect source of power. The contrast in illumination induces a voltage difference between the shadow and illuminated sections, resulting in an electric current."

SEG cells are less expensive to produce than solar cells. Each SEG cell is a thin film of gold on a silicon wafer, and an entire system is a set of four of these cells arrayed on a flexible, transparent plastic film. Experiments suggest the system, in use, is twice as efficient as commercial solar cells.

An SEG cell's shadow effect works best when it is half in light and half in shadow, "as this gives enough area for charge generation and collection respectively," says co-team leader Andrew Wee. When the SEG is entirely in shadow or in light, it doesn't produce a charge.

Gold in them that shadows

Image source: stockfour/Dayna More/Dmitry Naumov/Shutterstock/Big Think

To be sure, the amount of energy that NUS researchers have thus far extracted is small, but it's enough to power a digital watch. The researchers envision the SEG system harvesting ambient light to power smart phones and AR glasses that are used both outdoors and indoors. While such devices can run on solar batteries, solar is only replenished outdoors, and the SEG could "scavenge energy from both illumination and shadows associated with low light intensities to maximize the efficiency of energy harvesting," says Tan. It seems clear that we're on the cusp of the era of wearables — AR visionwear, smart fabrics, smart watches, and so on — and so Tan considers the arrival of the SEG "exciting and timely."

The researchers also note an additional application for which the SEG seems a natural: It can function as a self-powered sensor for monitoring moving objects. The shadow caused by a passing object would trigger the SEG sensor, which can then record the event.

Next up for the team is investigating constructing cells using other, less costly materials than gold to make them even less expensive to produce.

Ask an astronomer: What makes neutron stars so special?

Astrophysicist Michelle Thaller talks ISS and why NICER is so important.

  • Being outside of Earth's atmosphere while also being able to look down on the planet is both a challenge and a unique benefit for astronauts conducting important and innovative experiments aboard the International Space Station.
  • NASA astrophysicist Michelle Thaller explains why one such project, known as NICER (Neutron star Interior Composition Explorer), is "one of the most amazing discoveries of the last year."
  • Researchers used x-ray light data from NICER to map the surface of neutrons (the spinning remnants of dead stars 10-50 times the mass of our sun). Thaller explains how this data can be used to create a clock more accurate than any on Earth, as well as a GPS device that can be used anywhere in the galaxy.

Scientists create single-atom devices to supercharge computers

Researchers devise groundbreaking new methods to create and duplicate single-atom transistors for quantum computers.

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  • Researchers from the National Institute of Standards and Technology (NIST) and the University of Maryland were able to create single-atom transistors for only the second time ever.
  • They also achieved an unprecedented quantum mechanics feat, allowing for the future development of computers.
  • The tiny devices could be crucial in creating qubits, leading to next-generation technology.
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