Tag Archives: RMIT University

New Electronic Skin Reacts To Pain Like Human Skin

Researchers have developed electronic artificial skin that reacts to pain just like real skin, opening the way to better prosthetics, smarter robotics and non-invasive alternatives to skin grafts. The prototype device developed by a team at RMIT University (Australia) can electronically replicate the way human skin senses pain. The device mimics the body’s near-instant feedback response and can react to painful sensations with the same lighting speed that nerve signals travel to the brain.

Lead researcher Professor Madhu Bhaskaran said the pain-sensing prototype was a significant advance towards next-generation biomedical technologies and intelligent robotics.

Skin is our body’s largest sensory organ, with complex features designed to send rapid-fire warning signals when anything hurts,” Bhaskaran said. “We’re sensing things all the time through the skin but our pain response only kicks in at a certain point, like when we touch something too hot or too sharp. No electronic technologies have been able to realistically mimic that very human feeling of pain – until now. “Our artificial skin reacts instantly when pressure, heat or cold reach a painful threshold. “It’s a critical step forward in the future development of the sophisticated feedback systems that we need to deliver truly smart prosthetics and intelligent robotics.”

As well as the pain-sensing prototype, the research team has also developed devices made with stretchable electronics that can sense and respond to changes in temperature and pressure. Bhaskaran, co-leader of the Functional Materials and Microsystems group at RMIT, said the three functional prototypes were designed to deliver key features of the skin’s sensing capability in electronic form.

With further development, the stretchable artificial skin could also be a future option for non-invasive skin grafts, where the traditional approach is not viable or not working. “We need further development to integrate this technology into biomedical applications but the fundamentals – biocompatibility, skin-like stretchability – are already there,” Bhaskaran added.

Source: https://www.rmit.edu.au/

Mimicking Insect Wings To Fight Superbugs

The wings of cicadas and dragonflies are natural bacteria killers, a phenomenon that has spurred researchers searching for ways to defeat drug-resistant superbugs. New anti-bacterial surfaces are being developed, featuring different nanopatterns that mimic the deadly action of insect wings, but scientists are only beginning to unravel the mysteries of how they work.

In a post published in Nature Reviews Microbiology, researchers have detailed exactly how these patterns destroy bacteria stretching, slicing or tearing them apart. Lead author, RMIT University’s Distinguished Professor Elena Ivanova, said finding non-chemical ways of killing bacteria was critical, with more than 700,000 people dying each year due to drug-resistant bacterial infection.

The nanopillars on the surface of a dragonfly wing (magnified 20,000 times)

Bacterial resistance to antibiotics is one of the greatest threats to global health and routine treatment of infection is becoming increasingly difficult,” Ivanova said. “When we look to nature for ideas, we find insects have evolved highly effective anti-bacterial systems. “If we can understand exactly how insect-inspired nanopatterns kill bacteria, we can be more precise in engineering these shapes to improve their effectiveness against infections. “Our ultimate goal is to develop low-cost and scaleable anti-bacterial surfaces for use in implants and in hospitals, to deliver powerful new weapons in the fight against deadly superbugs.”

The wings of cicadas and dragonflies are covered in tiny nanopillars, which were the first nanopatterns developed by scientists aiming to imitate their bactericidal effects. Since then, they’ve also precisely engineered other nanoshapes like sheets and wires, all designed to physically damage bacteria cellsBacteria that land on these nanostructures find themselves pulled, stretched or sliced apart, rupturing the bacterial cell membrane and eventually killing them.

The new review for the first time categorises the different ways these surface nanopatterns deliver the necessary mechanical forces to burst the cell membrane. “Our synthetic biomimetic nanostructures vary substantially in their anti-bacterial performance and it’s not always clear why,” Ivanova explained. “We have also struggled to work out the optimal shape and dimensions of a particular nanopattern, to maximise its lethal power“While the synthetic surfaces we’ve been developing take nature to the next level, even looking at dragonflies, for example, we see that different species have wings that are better at killing some bacteria than others. “When we examine the wings at the nanoscale, we see differences in the density, height and diameter of the nanopillars that cover the surfaces of these wings, so we know that getting the nanostructures right is key.”

Source: https://www.rmit.edu.au/

Defective immune cells make us old

T cells are supposed to defend us from pathogens, but a new mouse study suggests they may also speed aging. Blocking inflammation caused by the cells or boosting their supply of a key metabolic molecule lessened the severity of some aging-related symptoms in rodents, raising the possibility these treatments could benefit older people. The discovery is “a fantastic result directly linking metabolism, inflammation, and aging,” says immunologist Kylie Quinn of RMIT University, Bundoora, in Australia. “They’ve done a really thorough job of making sure it’s the T cells” that are causing the mice to age quickly.

Our T cells let us down as we age, becoming weaker pathogen fighters. This decline helps explain why elderly people are more susceptible to infections and less responsive to vaccines. One reason T cells falter as we get older is that mitochondria, the structures that serve as power plants inside cells, begin to malfunction. But T cells might not just reflect aging. They could also promote it. Older people have chronic inflammation throughout the body, known as inflammaging, and researchers have proposed it spurs aging. T cells may stoke this process because they release inflammation-stimulating molecules.

To test that hypothesis, immunologist María Mittelbrunn of the University Hospital 12 October’s Health Research Institute and colleagues genetically modified mice to lack a protein in the mitochondria of their T cells. This alteration forces the cells to switch to a less efficient metabolic mechanism for obtaining energy.

By the time the rodents were 7 months old, typically the prime of life for a mouse, they already appeared to be in their dotage, the team reports today in Science. Compared with typical mice, the modified rodents were slow and sluggish. They had shrunken, weak muscles and were less resistant to infections. Like many elderly people, they suffered from weakened hearts and shed much of their body fatT cells from the altered mice poured out molecules that trigger inflammation, the team found, suggesting the cells could be partially responsible for the animals’ physical deterioration. “The immune system plays a role in increasing the velocity of aging,” Mittelbrunn says.

The scientists also tested whether they could slow the aging clock. First they dosed the mice with a drug that blocks tumour necrosis factor alpha (TNF-alpha), one of the inflammation-inducing molecules that T cells unleash; the treatment increased the animals’ grip strength, improved their performance in a maze, and boosted the heart’s pumping power.

Mittelbrunn and colleagues also gave the animals a compound that raises levels of nicotinamide adenine dinucleotide (NAD), a molecule that’s vital for metabolic reactions that enable cells to extract energy from food. NAD’s cellular concentrations typically decline with age, and the researchers found that ramping it up in the mice made them more active and strengthened their hearts.

Source: https://researchbank.rmit.edu.au/