Smart plugs are affordable, easy-to-use devices that bring smart home features to your home electronics. By offering scheduling capabilities and the ability to turn off devices remotely, and by reducing standby energy drain, smart plugs make it easy to save energy.
Source: How To Save Energy in Your Home With Smart Plugs
Print or share We Earthling posters to inspire others with your stories.
South Australia’s minister for energy and mining has told a conference of the oil and gas industry in Adelaide that his state government is “at your disposal”.
Tom Koutsantonis made the extraordinary comments during his address to the Australian Petroleum Production and Exploration Association national conference on Monday morning.
He said oil and gas companies were needed to achieve net zero by 2050, claiming “we cannot transform our economy to net zero without this industry”.
“We are thankful you are here. We are happy to a be recipient of Appea’s largesse in the form of coming here more often,” Koutsantonis said.
“The South Australian government is at your disposal, we are here to help and we are here to offer you a pathway to the future.”
Koutsantonis made the comments following a speech by federal resources minister, Madeleine King, who spoke about helping to develop a carbon capture and storage industry in Australia through the government’s future gas strategy.
King said it was important for Australia to remain a “reliable, essential” supplier of gas for domestic and export market as the world looked to reduce its emissions ahead of 2050.
She said capture and storage was a “necessary part of a wider decarbonisation effort”, with the government having released new acreage for greenhouse gas storage projects for the “first time in years”.
“The will is there, the knowhow is there,” said. “We want a regulatory system for carbon capture and storage that is robust and responsive and position Australians resources sector to bring new CCS projects on line.”
King also said the industry could obtain credits for lowering their emissions below baseline under the safeguard mechanism, but only “if they are verified and scientifically sound”.
The announcements were welcomed by the Woodside chief executive and chair of Appea, Meg O’Neill, who said it provided “a great opportunity to outline the ongoing role of gas in the energy transition”.
“The strategy will guide a realistic pathway for Australia into the future whereby responsible resource development is understood and can continue,” she said.
after newsletter promotion
But O’Neill said “regulatory certainty” was required if the government wanted to develop a carbon capture and storage industry.
“In Australia, I believe this is a technology that may have been judged too soon,” she said. “It works.”
Extinction Rebellion South Australia spokesperson Anna Slynn said the comments from King and Koutsantonis were “dangerous” given the imminent threat posed by the catastrophic risk of global heating, and pledged to make attendees “feel unwelcome” through protest outside the venue.
“The world’s climate scientists have been completely clear; there should be no further expansion of oil and gas if we want to avert complete climate catastrophe,” she said. “Life is in the balance. We will continue to make Appea feel unwelcome until they leave.
The International Energy Agency has said limiting global heating to 1.5C as set out in the Paris agreement meant there could be no new oil, gas or coal investment beyond 2021.
At another oil and gas conference last year, Koutsantonis was caught up in protests by Extinction Rebellion targeting fossil fuel producers over its role in driving climate change.
VISIONS: The EMIT Open Data Portal
Two recent studies by researchers at NASA’s Jet Propulsion Laboratory in Southern California used contrasting approaches to measure drops in human-caused emissions of the potent greenhouse gas methane in recent years in the Los Angeles region.
In the first study, published in February in Environmental Research Letters, scientists analyzed data from ground-based sensors scattered around four counties in densely populated Southern California: Los Angeles, Orange, San Bernardino, and Riverside. They found emissions fell by about 7% between 2015 and 2020 – a reduction of 33 million pounds (15 million kilograms) of methane released per year.
The second study, published in March in Environmental Research Communications, compared emissions from a belt of oil refineries across the South Bay area of Los Angeles during the first summer of the COVID-19 pandemic to those observed three years earlier. Using data from a NASA airborne instrument, researchers saw that most of the facilities they identified as methane sources in the earlier campaign were no longer emitting the greenhouse gas, leading to a 73% reduction in measured emissions. While such a reduction around COVID disruptions was not necessarily surprising, the result was important for demonstrating scientists’ ability to track point sources of methane.
Methane has a much shorter atmospheric lifespan than carbon dioxide – around 12 years, compared to centuries for carbon dioxide – but it absorbs much more energy while it exists in the atmosphere. Therefore, reducing human-caused emissions of the gas is a particularly effective way to make significant, short-term impacts on global climate change.
“These papers demonstrate that methane reductions are not only possible, they’re measurable through persistent monitoring,” said Andrew Thorpe, lead author of the COVID-period study and a JPL research technologist.
That two studies could use different techniques to identify and quantify emissions trends is crucial for generating confidence in the conclusions drawn from methane observations, added Vineet Yadav, a JPL data scientist and lead author of the first paper.
“The important thing is to determine whether emissions are increasing or declining, and for that it’s helpful to have more than one approach,” said Yadav, whose study employs two techniques. “If you are turning the information over to decision-makers, you have to be sure.”
Yadav’s paper is based on measurements from eight spectroscopic sensors that were installed as part of the Megacities Carbon Project, a multiagency collaboration currently monitoring greenhouse gases in the Los Angeles, Indianapolis, and Washington areas. The sensors have been gathering data across a large swath of Southern California since 2015 and enabled researchers to study an area that stretches from the beaches of Malibu in the west to the mountains and deserts of San Bernardino and Riverside counties in the east. It also extends south through all of Orange County.
The researchers found that month-to-month fluctuations in methane concentrations measured at each sensor tower gradually fell from 2015 to 2020 and well into 2022 – a strong indication that local emissions of the gas were also decreasing. Then, using a mathematical model to estimate the emissions decrease, Yadav and colleagues found the areas covered by the Granada Hills and Ontario sensors accounted for much of the drop in annual emissions from 2015 to 2020.
Although the paper doesn’t cite causes of the emission reductions in those two locales, Yadav suspects they resulted from better management of natural gas pipelines and equipment, which in turn led to lower fugitive – or accidental – methane releases. Improved infrastructure at a massive waste site near Granada Hills likely also played a role.
Rather than analyzing data from ground sensors, the study focusing on oil refineries uses measurements made by an imaging spectrometer called AVIRIS-NG (Airborne Visible/Infrared Imaging Spectrometer-Next Generation). Attached to the bottom of an aircraft, the instrument can detect greenhouse gas emissions from individual facilities or even pieces of equipment by looking at how the gases absorb sunlight.
In 2016 and 2017, AVIRIS-NG was flown over 22,000 square miles (57,000 square kilometers) of the state as part of the California Methane Survey. From July to September 2020, researchers retraced some of those flight paths over refineries and power plants in Los Angeles County and over oilfields in central California’s San Joaquin Valley. The flights were funded by NASA’s Earth Science Division, the California Air Resources Board, and the California Energy Commission.
The 2020 surveys over Los Angeles identified only 11 plumes from five refinery sources, with a total emissions rate of about 712 pounds (323 kilograms) of methane per hour. The 2016 and ’17 flights had found 48 plumes from 33 sources, with a total emissions rate of roughly 2,639 pounds (1,197 kilograms methane) per hour. The drop correlates with an 18% decrease in monthly production in Southern California refineries between the two flight campaigns, the scientists noted, citing data from the California Energy Commission. The study also found that emissions from oilfields in and around the city of Bakersfield in central California fell 34.2%, correlating with a 24.2% drop in oil production.
Thorpe said that reduced production during the pandemic due to lower demand for fuel and depressed oil prices could have led to the drop in methane emissions, as oilfields and refineries emitted less methane during operations. However, he added, improved equipment maintenance and mitigation efforts at those facilities between 2016 and 2020 can’t be ruled out as a factor.
The National Oceanic and Atmospheric Administration’s estimate of global atmospheric methane concentration accelerated after 2020, “underscoring the critical need to reduce emissions,” Thorpe writes in the paper. Being able to accurately detect and measure emissions is a key step, both he and Yadav said.
For decades, NASA has been developing and using innovative tools to observe changes in greenhouse gas concentrations driven by both human activity and natural variations. For instance, in 2022 the agency launched the EMIT mission (short for the Earth Surface Mineral Dust Source Investigation), which can identify methane point-source emissions. Additionally, JPL is partnering with Carbon Mapper and Planet Labs PBC to launch satellites with greenhouse-gas monitoring capabilities. The agency is also working to make data more accessible and combining it with other sources to make user experiences easier and more efficient.
Andrew Wang / Jane J. Lee
Jet Propulsion Laboratory, Pasadena, Calif.
626-379-6874 / 818-354-0307
[email protected] / [email protected]
This animation shows a series of waves, called Kelvin waves, moving warm water across the equatorial Pacific Ocean from west to east during March and April. The signals can be an early sign of a developing El Niño, and were detected by the Sentinel-6 Michael Freilich sea level satellite. Credit: NASA/JPL-Caltech
The most recent sea level data from the U.S.-European satellite Sentinel-6 Michael Freilich indicates early signs of a developing El Niño across the equatorial Pacific Ocean. The data shows Kelvin waves – which are roughly 2 to 4 inches (5 to 10 centimeters) high at the ocean surface and hundreds of miles wide – moving from west to east along the equator toward the west coast of South America.
When they form at the equator, Kelvin waves bring warm water, which is associated with higher sea levels, from the western Pacific to the eastern Pacific. A series of Kelvin waves starting in spring is a well-known precursor to an El Niño, a periodic climate phenomenon that can affect weather patterns around the world. It is characterized by higher sea levels and warmer-than-average ocean temperatures along the western coasts of the Americas.
Water expands as it warms, so sea levels tend to be higher in places with warmer water. El Niño is also associated with a weakening of the trade winds. The condition can bring cooler, wetter conditions to the U.S. Southwest and drought to countries in the western Pacific, such as Indonesia and Australia.
The Sentinel-6 Michael Freilich satellite data shown here covers the period between the beginning of March and the end of April 2023. By April 24, Kelvin waves had piled up warmer water and higher sea levels (shown in red and white) off the coasts of Peru, Ecuador, and Colombia. Satellites like Sentinel-6 Michael Freilich can detect Kelvin waves with a radar altimeter, which uses microwave signals to measure the height of the ocean’s surface. When an altimeter passes over areas that are warmer than others, the data will show higher sea levels.
“We’ll be watching this El Niño like a hawk,” said Josh Willis, Sentinel-6 Michael Freilich project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “If it’s a big one, the globe will see record warming, but here in the Southwest U.S. we could be looking at another wet winter, right on the heels of the soaking we got last winter.”
Both the U.S. National Oceanic and Atmospheric Administration (NOAA) and the World Meteorological Organization have recently reported increased chances that El Niño will develop by the end of the summer. Continued monitoring of ocean conditions in the Pacific by instruments and satellites such as Sentinel-6 Michael Freilich should help to clarify in the coming months how strong it could become.
“When we measure sea level from space using satellite altimeters, we know not only the shape and height of water, but also its movement, like Kelvin and other waves,” said Nadya Vinogradova Shiffer, NASA program scientist and manager for Sentinel-6 Michael Freilich in Washington. “Ocean waves slosh heat around the planet, bringing heat and moisture to our coasts and changing our weather.”
Sentinel-6 Michael Freilich, named after former NASA Earth Science Division Director Michael Freilich, is one of two satellites that compose the Copernicus Sentinel-6/Jason-CS (Continuity of Service) mission.
Sentinel-6/Jason-CS was jointly developed by ESA (European Space Agency), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), NASA, and NOAA, with funding support from the European Commission and technical support on performance from the French space agency CNES (Centre National d’Études Spatiales). Spacecraft monitoring and control, as well as the processing of all the altimeter science data, is carried out by EUMETSAT on behalf of the European Union’s Copernicus programme, with the support of all partner agencies.
JPL, a division of Caltech in Pasadena, contributed three science instruments for each Sentinel-6 satellite: the Advanced Microwave Radiometer, the Global Navigation Satellite System – Radio Occultation, and the Laser Retroreflector Array. NASA also contributed launch services, ground systems supporting operation of the NASA science instruments, the science data processors for two of these instruments, and support for the U.S. members of the international Ocean Surface Topography Science Team.
To learn more about Sentinel-6 Michael Freilich, visit:
https://www.nasa.gov/sentinel-6
Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
[email protected] / [email protected]
A University of Queensland study has found humpback whales sing louder when the wind is noisy, but don’t have the same reaction to boat engines.
Research lead Dr Elisa Girola from UQ’s Faculty of Science said this quirk of whale evolution could have consequences for breeding and behaviour.
“Humpback whales evolved over millions of years with noise from natural sources but noise from human-made vessels is foreign to their instincts,” Dr Girola said.
“It’s a surprising finding given engine noise has a similar frequency range to the wind.
“It’s possible the whales are picking out other differences such as wind noise being broadband and the same over large areas, while vessel noise is generated by a single-point source with specific peaks in frequency.
“We don’t know yet if this lack of response to boat noise is making whales communicate less effectively or making breeding practices more difficult.
“Male humpback whale singing is probably used to mediate reproductive interactions, but we can’t say if vessel noise is interfering.”
The audio data for the study was collected in late 2010 off Peregian Beach in Queensland, during the whales’ southward migration from breeding grounds in the lagoon of the Great Barrier Reef to feeding grounds in Antarctica.
Whale songs were recorded using an acoustic array of five hydrophone buoys, which sent signals back to the beach.
A 19-metre fishing boat was introduced to produce vessel noise.
The researchers say it is possible that humpback whales are using other strategies to compensate for vessel noise.
“Even with a 19-metre boat making a racket, the whales just didn’t sing any louder,” Dr Girola said.
“There are a few things going on — they might be using ‘spatial release from masking’, which is the ability to discriminate between audio signals coming from different directions.
“Or there’s ‘comodulation release from masking’ which is the ability to discriminate between signal and noise when the noise has distinctive frequency components and at least some of these components are not overlapping with the signal.
“There’s still so much more research to be done.
“Understanding humpback whales’ response to noise is important for developing mitigation policies for human activities at sea.
“I’m sure these beautiful, mysterious creatures will continue to surprise and amaze us.”
An international team including Simon Steidle from the Quaternary Research Group at the Department of Geology at the University of Innsbruck has reconstructed the evolution of groundwater in the Great Basin, USA — one of the driest regions on Earth — up to 350,000 years into the past with unprecedented accuracy. The results shed new light on the effects of climate change on water supply and provide important insights for the sustainable use of groundwater resources. The study was published in the journal Nature Communications Earth & Environment.
The team led by Christoph Spötl has been investigating the famous “Devils Hole” cave system in Nevada since 2010 — during spectacular expeditions. Using the calcite deposits in the cave, the researchers have already reconstructed the development of the water level in the cave up to several hundred thousand years ago. In the current study, this information has now been combined with a numerical groundwater model for this arid region.
“Based on our extensive sampling in Devils Hole, we have a large amount of data that provides information on the evolution of the water table. By combining this with groundwater models from the US Geological Survey, we can now draw quantitative conclusions about changes in precipitation for the entire region over the last 350,000 years using the precise data from the cave,” explains the geologist Simon Steidle. In drylands like the southwest of the USA, precipitation is particularly important and groundwater data is a mirror of changes in the hydroclimate. “The results can be useful for developing water management strategies and sustainable use of groundwater resources, such as how much water can be withdrawn for agricultural purposes.”
Drought increases sensitivity
The new data suggest that the elevation of the water table in Devils Hole was three to four times more sensitive to groundwater recharge during dry climates than during wetter climates of the past. “Given that drought conditions will likely increase even more in the future due to the ongoing climate crisis, our results highlight the vulnerability of large aquifers, and thus the alteration of the most important freshwater resource in this area of the United States,” Steidle said. The minimum groundwater level in Devils Hole during the peak of the interglacial warm periods was no more than 1.6 metres below today’s level, which corresponds to a decrease in groundwater recharge of less than 17 % compared to today’s conditions. During the glacial periods, however, the level was at least 9.5 metres above today’s level, which means an increase in groundwater recharge of almost 250% compared to today’s conditions.
The new information is relevant especially for the already highly endangered Devils Hole pupfish, a fish measuring just a few centimetres whose only habitat is the water in Devils Hole. The habitat of this species is thus the smallest of all known vertebrates (about half the size of an average classroom). Even small changes in water availability triggered by abstraction of groundwater for irrigation purposes or by climate change are of utmost importance for its survival.
Garden pests are a fact of life for gardeners. There’s no escaping it — lots of creatures want to feed on your hard-won harvest. They’ll chomp away happily if given the chance. That’s why many gardeners have come to love bugs. Not all bugs, of course, but a subset called beneficial insects.
You’re already familiar with the beneficial insects that pollinate the flowers and food crops, like bees and butterflies. Other beneficial insects help gardeners by consuming pests that go after our flowers and vegetable gardens.
Read on to find out which insects will manage the pesty ones, how to attract beneficial insects, and how to reframe the way you think about garden pests.
Some gardeners might think that dousing their gardens with pesticides is the answer to nibbling insects. But there are serious downsides to using chemical pesticides. Pesticides have negative impacts on human health and can persist in the environment, harming soil health, polluting waterways, and endangering wildlife.
In addition, by applying chemical pesticides, gardeners destroy some of their best weapons against pests — beneficial insects.
Many gardeners know the sinking feeling of discovering their beloved plants destroyed by unwanted guests. Slugs, aphids, and other garden pests have little regard for the hard work we put into our gardens. But, what nature destroys, nature can replenish. Sometimes, if we step aside, nature will give us just what we need — in this case, hard-working beneficials that keep garden pests in check.
One way that beneficial insects help in the garden is by preying on the bugs we don’t want. Insect predators can consume thousands of harmful pests.
Most of us think of ladybugs as being red with black spots, but there are hundreds of species of ladybugs. Also known as ladybird beetles, almost all ladybugs are voracious eaters of aphids as well as spider mites and scale insects.
You can find them on the underside of leaves, working for you. Even their larvae eat aphids. Ladybugs feed on nectar and pollen as well as garden pests, so that makes them good pollinators, too. Be sure to feature hearty flowering plants to keep them happy.
Praying mantids are one of the larger insects you’ll see in your garden. Depending on the species, adults can reach 2 to 12 inches long, although in North America, you’ll generally find them within the 2- to 5-inch range. They may look like they are praying, but they spend their time preying on a variety of insects and animals. Some species are large enough to eat mice. Others eat bugs such as aphids and spiders.
Praying mantids aren’t picky eaters. They’ll munch down any grasshoppers eating your plants, but they’ll also eat helpful insects — including other mantids. They’ll even eat hummingbirds. As long as you don’t introduce an outsized species, you should be able to reap their rewards without losing what you value.
Preying mantids prefer hiding in tall grasses, shrubs, and heavy foliage. A healthy garden with plenty of places to hide should attract enough to help you out.
Not all flies are pests. Some, like the hoverfly, pollinate plants and hunt pests for our benefit. Hoverflies resemble a dainty wasp, but a closer look reveals no stinger. Hoverfly larvae feast on thrips, aphids, mealybugs, and caterpillars.
Attract hoverflies by offering a variety of flowering plants in your garden.
Dragonflies won’t save your cucumbers, but their diet can make sitting in your yard a lot more enjoyable. Dragonflies eat other flying insects — gnats, flies, and mosquitos. They can pack away hundreds of mosquitos in a day. They do take down an occasional butterfly, but as mosquitos can spread disease, that’s probably an okay trade-off.
Dragonflies spend part of their lives in water, but they travel pretty far when they leave it. If you have a pond or wetlands nearby, you should see plenty. If not, adding a small pond can attract them.
Parasitoids are creatures that set up house in another animal and kill it from the inside out. The most common parasitoid you’re likely to see is the parasitic, or braconid, wasp.
Stumbling across one of these babies (literally, they’re larvae) on your tomato plant is equal parts unnerving and fascinating. In a pretty amazing feat, the adult wasp lays its eggs inside a tomato hornworm. Sometime later, the larvae eat their way out, leaving a heavy worm carcass with dozens of eerie-looking white cocoons on the outside.
You may jump out of your skin when you see one, but those weird little buggers will save your tomato plant. Parasitic wasps also lay their eggs in grubs that feed on the roots of your plants. If you find any parasitic wasp cocoons, leave them alone. When they hatch, these beneficial insects will lay their own eggs and keep garden pests in check.
Gardeners used to bring out the heavy artillery against the first sign of pests, but that’s changing. The effects of human behavior on the environment grow clearer every day. People are looking for ways to live in harmony with nature, not fight against or conquer it.
That just may mean changing our perspective about what we deem as pests. The fact is that if you have a garden, you’re going to have bugs. But beneficial insects — including those mentioned above and a wide variety of pollinators — can be our allies if we recognize how to work with them. Even the ones we consider pests can be tolerated in a well-managed garden. If you have an otherwise healthy garden, they shouldn’t result in an all-out infestation.
Feature image: mature hoverfly, Adobe Stock.
This article was originally published on May 2, 2022.
Small-scale wildlife surveys can reveal the health of entire ecosystems, new research shows.
Monitoring wildlife is one of the most costly and difficult aspects of conservation, and often depends on long-term observations in individual species.
But the study reveals a new and effective method.
It focusses on “interactions” between species, such as insects pollinating flowers or birds feeding on plants.
The results show that a small snapshot of interactions is a reliable indicator of the health of an entire community of species. Specifically, the study looked at whether these communities are “persistent” or not — meaning whether all species are fine or if any are declining to extinction.
The study was carried out by the University of Exeter, McGill University, the University of Toronto, Princeton University and MIT.
“All communities of plants and animals are supported by an underlying network of interactions between species,” said Dr Christopher Kaiser-Bunbury, from the Centre for Ecology and Conservation at Exeter’s Penryn Campus in Cornwall.
“Our study — which combines theory, statistics and real-world data — shows that examining a few of these interactions can provide ‘big picture’ conclusions about ecosystem health.
“This information is essential for policymakers, scientists and societies, as we try to tackle the global biodiversity crisis.”
When environmental conditions change, interactions between species often change too — providing an early indicator of wider problems.
As such, the study’s method can identify patterns more quickly than some traditional conservation monitoring — which is vital given the rapid changes being caused by human activity.
“Using minimal resources, we can rapidly assess both the persistence of entire ecological networks and the expected success of restoration,” said Dr Benno Simmons, also from Exeter’s Centre for Ecology and Conservation.
“Our method is especially effective at identifying when an ecological community is not persistent — allowing for rapid detection of extinction risk.”
Frogs in Puerto Rico are croaking at a higher pitch due to global heating, scientists have found.
The frogs appear to be decreasing in size at warmer temperatures, which causes their croaks to become high pitched. If the trends continue, the heat could become too much for the sensitive amphibians to survive successfully, researchers have said.
The call of the coquí frog is well known to most who have spent time in Puerto Rico. It is named for its two-note call “co-qui”, which rings out throughout the island every night.
Male coquí frogs use their distinctive call to mark their territory and warn off rivals, but scientists have noticed that it is changing.
Peter Narins of the University of California, Los Angeles, has been studying their croaks for 23 years. While recording the sounds along the slopes of El Yunque mountain in Puerto Rico, he and his team found that the calls changed depending on the altitude of the frogs.
Amphibians are very sensitive to changes in temperature, and the higher on the mountains they were, the cooler it was. The frogs on the mountain peaks, therefore, were found to be larger than ones sitting in warm valleys, and this meant their call was different.
Nairns said: “Coquí that produced short, high-pitched calls at high rates lived near the base of the mountain, while the calls of animals living near the mountain’s peak were longer, lower-pitched, and repeated less frequently.”
Two decades after first recording their sound, Nairns returned to the mountains with a colleague, Sebastiaan Meenderink. The pair found that every frog call, no matter where it was on the mountain, had become higher pitched.
“In order to record a call with certain characteristics we had to move to a slightly higher altitude,” said Meenderink. “It was as if all the animals had moved up the mountain.”
after newsletter promotion
The scientists are concerned that the frogs will keep crawling up the mountain to escape higher temperatures at the bottom, but they will eventually run out of room.
“For now, the consequences are not dire,” said Meenderink. “A barely perceptible change in frog body size and call has little impact on the environment. However, if left unabated, the temperature increase will eventually cause a collapse of the coquí population, which will be catastrophic for the Puerto Rican ecosystem.”
Newly developed “smart” coatings for surgical orthopedic implants can monitor strain on the devices to provide early warning of implant failures while killing infection-causing bacteria, University of Illinois Urbana-Champaign researchers report. The coatings integrate flexible sensors with a nanostructured antibacterial surface inspired by the wings of dragonflies and cicadas.
In a new study in the journal Science Advances, a multidisciplinary team of researchers found the coatings prevented infection in live mice and mapped strain in commercial implants applied to sheep spines to warn of various implant or healing failures.
“This is a combination of bio-inspired nanomaterial design with flexible electronics to battle a complicated, long-term biomedical problem,” said study leader Qing Cao, a U. of I. professor of materials science and engineering.
Both infection and device failure are major problems with orthopedic implants, each affecting up to 10% of patients, Cao said. Several approaches to fighting infection have been attempted, but all have severe limitations, he said: Biofilms can still form on water-repelling surfaces, and coatings laden with antibiotic chemicals or drugs run out in a span of months and have toxic effects on the surrounding tissue with little efficacy against drug-resistant strains of bacterial pathogens.
Taking inspiration from the naturally antibacterial wings of cicadas and dragonflies, the Illinois team created a thin foil patterned with nanoscale pillars like those found on the insects’ wings. When a bacterial cell attempts to bind to the foil, the pillars puncture the cell wall, killing it.
“Using a mechanical approach to killing bacteria allowed us to bypass a lot of the problems with chemical approaches, while still giving us the flexibility needed to apply the coating to implant surfaces,” said pathobiology professor Gee Lau, a coauthor of the study.
On the back side of the nanostructured foil, where it contacts the implant device, the researchers integrated arrays of highly sensitive, flexible electronic sensors to monitor strain. This could help physicians watch the healing progress of individual patients, guide their rehabilitation to shorten the recovery time and minimize risks, and repair or replace devices before they hit the point of failure, the researchers said.
The engineering group then teamed up with veterinary clinical medicine professor Annette McCoy to test their prototype devices. They implanted the foils in live mice and monitored them for any sign of infection, even when bacteria were introduced. They also applied the coatings to commercially available spinal implants and monitored strain to the implants in sheep spines under normal load for device failure diagnosis. The coatings performed both functions well.
The prototype electronics required wires, but the researchers next plan to develop wireless power and data communications interfaces for their coatings, a crucial step for clinical application, Cao said. They also are working to develop large-scale production of the nanopillar-textured bacteria-killing foil.
“These types of antibacterial coatings have a lot of potential applications, and since ours uses a mechanical mechanism, it has potential for places where chemicals or heavy metal ions — as are used in commercial antimicrobial coatings now — would be detrimental,” Cao said.
The National Science Foundation and the U.S. Congressionally Directed Medical Research Programs supported this work.
Recent Comments