University of Michigan researchers have demonstrated that behavioral rules underpinning the Japanese art of folding can expand the capabilities of these machines, creating potential for greater use in fields as diverse as medical equipment and infrastructure sensing.

“We’ve come up with a new way to design, fabricate and actuate microbots,” said Evgueni Filipov, U-M assistant professor of civil and environmental engineering. “We’ve been the first to bring advanced origami folding capabilities into one integrated microbot system.”

Their bots can form one shape, complete a task, then reconfigure into a second shape for an additional task, and so on.

The latest research from the team, which includes Kenn Oldham, a U-M professor of mechanical engineering, Ph.D. student Yi Zhu and graduate research assistant Mayur Birla, appears in Advanced Functional Materials.

To date, most microbots have limited movements, which hampers their ability to perform useful tasks. To increase their range of motion, they need to be able to fold at large angles. U-M’s team has created microbots that can fold as far as 90 degrees and more. Larger folds allow microbots to form more complex shapes.

U-M’s unique approach enables its microbots to complete their range of motion up to 80 times per second, a faster pace than most can operate.

Microbots using origami principles often require an outside stimulus to activate, such as heat inside a body or a magnetic field applied to the microbot. U-M’s utilize a layer of gold and a layer of polymer that act as an onboard actuator — meaning no outside stimulus is needed.

While the microbots are currently controlled by a tether, eventually, an onboard battery and a microcontroller will apply an electric current in the systems.

“When current passes through the gold layer, it creates heat, and we use heat to control the motions of the microbot,” Filipov said. “We drive the initial fold by heating the system, then we unfold by letting it cool down.

“To get something to fold and stay folded, we overheat the system. When we overheat, we can program the fold — change where it comes to rest.”

These capabilities allow microbots to function elastically and plastically — giving them the ability to recover their original shape.

The research was supported by the Defense Advanced Research Projects Agency and the U-M College of Engineering Dean’s Fellowship.

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Sean Martin, a researcher in the Department of Civil and Environmental Engineering from Florida State University, is working with an interdisciplinary team of scientists to examine wind resource characteristics at nine different locations in Florida. Their analysis will help the wind industry and policymakers know how viable wind energy production using developing technologies could be.

Sean Martin, a researcher in the Department of Civil and Environmental Engineering

Their work was published in the journal Applied Energy.

“With advances in turbine technology, taller towers, larger rotor diameter and new control systems, we will be able to provide low-cost wind power to low-wind regions, such as Florida and the Southeast,” Martin said. “The increased hub heights and taller turbines can take advantage of greater wind speeds that occur higher up to harvest more wind power.”

Compared to states like Texas or Iowa, the wind in Florida is not something wind farms can profitably capture at the moment. Wind speeds are slower because of increased surface friction and turbulence caused by buildings, trees and other obstructions. Most utility-scale turbines installed in the United States are west of the Mississippi River, where more favorable wind speeds, greater than 13 miles per hour, are prevalent.

But using new tools that can capture wind energy at higher elevations, where wind speeds are faster, might make wind energy feasible.

Arda Vanli, associate professor in the Department of Industrial and Manufacturing Engineering

So how tall are these turbines? The average height of most existing on-shore turbines from the ground to the top of the blades is more than 380 feet, similar to a 32-story building. The new, taller turbines are almost twice the height at 660 feet, close to the height of a 55-story building, and are the kind of wind turbines that will be most useful in Florida.

Martin is collaborating with Arda Vanli, an associate professor of industrial and manufacturing engineering, and Sungmoon Jung, an associate professor of civil and environmental engineering.

“I don’t think anybody can predict the timing for wind energy,” Jung said. “We almost had it a few years ago. There was a private company that proposed a wind farm in Florida, but the company withdrew the plan because the technology at the time was not economical enough. I hope we will see wind energy in the future as technology improves.”

Sungmoon Jung, associate professor in the Department of Civil and Environmental Engineering

One of the things the researchers are looking at is the capacity of wind turbines to operate at different sites. Wind speed varies, so turbines must be able to spin at different velocities. Researchers want to know what percentage of time in a year that the turbine can operate at full capacity. In general, turbines that generate at least 30 percent of their total capacity are more economical for utility-scale wind power. The data will be able to predict the best areas in Florida to place the new turbines based on their ability to produce wind energy at specific sites.

“The key is finding and identifying characteristic patterns in the wind data,” Martin said. “Once we establish the patterns, the data can assist in site selection and can improve energy estimation measures to help industry and policymakers make decisions on where wind farms are most profitable.”

There are other factors the researchers must consider when choosing a site for a wind farm. Safety for birds, noise from rotors and the fact that some people may find wind turbines unsightly are all considerations.

When including some of these elements with wind speed data, the scientists found that the best locations for wind farms appear to be in rural areas of northwest, central and southern Florida.

“Site selection is an important decision, especially in low-wind power areas,” Vanli said. “Transporting huge wind turbines to these locations is a significant investment and having good data can eventually determine whether the investment will be successful or not.”

Wind energy is gaining significant attention both from academia and in industry. New, affordable methods for generating renewable energy are on the horizon. Wind farms could be viable in Florida within this decade, and turbines even taller than the ones used for this research could be more prevalent in the future.

“The real question is whether factors such as public perception, acceptance and environmental factors will prevent this resource from being developed,” Martin said. “We hope the research will add additional renewables to the U.S. energy portfolio and can offset our reliance on a single fuel source, adding energy security to meet a growing need.”

UNSW Sydney researchers collected and analysed samples of whale blow — similar to mucus from a human nose — and found “significantly less” microbial diversity and richness on the return leg of the whales’ migration, indicating the whales were likely in poorer health than when their journey began.

Microbial diversity accounts for the wide array of microorganisms — the smallest forms of life.

Lead author Dr Catharina Vendl, UNSW Science researcher, said the study, published in Scientific Reports this week, provided the first evidence whales’ airway microbiota was a potential indicator of a whale’s overall health.

East Australian humpback whales complete, on average, an arduous 8000-kilometre round trip between Antarctica and Queensland from May to November each year, fasting for most of their journey.

“The physical strains of the humpback’s migration likely affected the microbial communities in the whales’ airways — so, our findings are key to further developing the analysis of airway microbiota as a non-invasive method for monitoring the immune function and overall health of whales and dolphins,” Dr Vendl said.

“People enjoy whale-watching season, but with it comes reports of whales becoming stranded. Although humpback whale stranding events occur naturally and regularly to injured and young whales, it is crucial to monitor the population health of this iconic species to ensure its long-term survival.

“Humpback whales do not only play an essential role in their marine ecosystem but also represent an important economic resource, because whale watching is a booming industry in many Australian cities and around the world.”

Humpback whales were almost hunted to extinction. The last whaling station in NSW, at Byron Bay, closed in 1962 because so few whales could be found.

Humpback whales are now protected throughout Australia, and in NSW are listed as a vulnerable species under the Biodiversity Conservation Act 2016.

Dr Vendl, who has a background in veterinary science, said it was amazing the east and west Australian humpback whale populations had recovered well in the years since whaling stopped.

“So, these whale populations are not endangered, but that doesn’t necessarily mean things will stay that way,” she said.

Collecting whale ‘snot’

Dr Vendl said it was important to find a non-invasive method to study whale health, because many whale populations around the world were endangered — yet scientists still knew fairly little about whales’ physiology.

“Many whale species are at or near the top of their food chain — so, a whale’s general health can be a good indicator of the health of their marine ecosystem,” she said.

“Humpback whales mostly live on tiny creatures called krill, but because there is less of this preferred food along the east Australian coast and it’s such a huge effort for them to open their mouths to feed, they rely on energy stored in their blubber.

“Fasting is therefore a major physiological strain during the whales’ migration.”

Dr Vendl collected airway mucus from 20 whales in Hervey Bay, Queensland, during the humpback’s return leg to Antarctica when the whales were several months into their migration in August 2017.

The researchers then analysed and compared the whales’ blow microbiota to samples Macquarie University scientists collected near Sydney in May and June 2017, for a separate study, when the whales were at the start of their migration.

UNSW Science Professor Tracey Rogers pioneered the technique the UNSW researchers used to examine the whales’ airway microbial communities, more than a decade ago.

Dr Vendl said researchers wanted to determine if there was a significant difference between the microbial communities of the whales at the start of and later on in their migration.

“I used two methods to collect the whales’ blow while working from a boat. For one method, I flew a waterproof drone over the whales which carried a petri dish,” she said.

“It was pure luck waiting for the whales to exhale at the same time the drone was within range for droplets from their blow to settle on the petri dish.

“My second technique was a 4.6-metre long telescopic pole with petri dishes attached to the end. In Hervey Bay, the whales are curious and approach boats.

“So, I held the pole out and waited until the whales exhaled and then collected their samples that way.”

Migration pressure link to potential poor health

The study found the whales’ respiratory microbiota was severely depleted in diversity and richness the longer they fasted during their migration.

Dr Vendl said such changes often reflected a compromised state of health in the airways of humans.

“We concluded the physical strains of the migration, likely in addition to the exposure to marine pollutants, compromise the whales’ immune systems and consequently cause a shift in the whales’ airway microbiota.

“Our findings are the first to provide good evidence of a connection between the whales’ airway bacterial communities, their physiology and immune function — something that has been established in humans.”

Dr Vendl said a high level of bacterial variety and richness in respiratory microbiota was a sign of healthy airways in humans.

“I researched literature in human medicine: when you have a respiratory disease in a person, it also means the bacterial communities in their airways have changed and are usually depleted,” she said.

“We had no idea if we would find a similar pattern in whales, but we at least showed the initial evidence for that occurring.”

New potential for non-invasive methods

Dr Vendl said she hoped her research would lead to further study in non-invasive techniques to monitor whale health in populations around the world.

“Our findings showed the first evidence of a link between whales’ respiratory microbiota and their overall health, but more research needs to be done,” she said.

“Analysing whale blow to assess and monitor whale health opens up more possibilities for the use of non-invasive techniques, such as photogrammetry — where you fly a drone to film and measure whales to determine how much blubber they have and things like that.

“Other methods were outside the scope of my PhD, but it’s important for researchers to experiment with and refine new techniques to assess their effectiveness in helping whale conservation.”

Recently, cutting-edge techniques in DNA sequencing, 3D imaging, and computation have opened up opportunities for investigating historical processes. In a new study published in Evolution, researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) and collaborators from the University of the Ryukyus investigated evolutionary and ecological changes in ants in the South Pacific archipelago of Fiji to examine a controversial theory for how evolution occurs on islands.

“Islands like Fiji, which are small and remote, act as perfect natural laboratories to study the interplay between ecological and evolutionary processes,” said Dr. Cong Liu, first author and former PhD student from the OIST Biodiversity and Biocomplexity Unit. “But until recently, there haven’t been many studies on ants.”

The team focused on Strumigenys trap-jaw ants, the genus with the greatest number of ant species in Fiji. They collected many specimens of trap-jaw ants during an expedition to Fiji in 2007.

The researchers set out to examine how well the changes in appearance and distribution observed in trap-jaw ants over time fit with a theory called the taxon cycle hypothesis, which describes how species colonize and evolve on islands. According to this theory, species pass through a predictable “life cycle” of colonization, geographic range expansion, decline, and (sometimes) extinction, with this cycle then restarted by a new colonizer.

Cracking the colonization stage

The scientists extracted and sequenced DNA from Strumigenys species endemic to the Fijian archipelago — in other words, they are only found in these islands. The team also included samples of the trap-jaw ants more regionally and globally distributed relatives. Based on the DNA sequences, the scientists constructed an evolutionary tree, showing how closely related all the species were.

“We discovered that all 14 of the trap-jaw ant species endemic to Fiji were descended from a single original colonizer, rather than from multiple colonizers,” Dr. Liu explained.

These results contradict what would be expected by the taxon cycle hypothesis, which predicts that later colonizers arrive and kickstart new taxon cycles of radiation and decline.

“There are a few reasons why repeated colonizations may not have occurred,” said Dr. Liu. He explained that the first trap-jaw colonizers could have diversified and occupied all the niches, closing the door to any newcomers. Or perhaps, he added, the Fijian archipelago is so remote that additional colonizers never arrived.

Revealing the radiation stage

According to the taxon cycle hypothesis, a species first colonizes an island, and then undergoes a huge expansion in range, specializing to the available niches in each habitat.

When the scientists looked at the distribution of the 14 trap-jaw species endemic to Fiji, they found that soon after colonization, the initial lineage split in two, with one giving rise to species living in lowland habitats, and one giving rise to species in upland habitats.

The scientists then measured key morphological features of the ants to determine whether they established their niches through adaptive radiation. “Adaptive radiation often occurs on islands, with the most iconic example being Darwin’s finches,” said Dr. Liu. “This sudden explosion in abundance, diversity and appearance is often due to a greater number of empty niches that the ants can adapt to, due to a lack of competitors or predators.”

The scientists used micro-CT scanners to create 3D models of each Fijian ant species. They also measured the size of the ants’ bodies, jaws (mandibles) and eyes.

“We saw a clear diversification of form that is associated with the niches they are occupying, which was clearly a result of adaptive radiation,” said Dr. Liu. In general, the ants in the upland lineage evolved larger bodies, allowing them to catch larger prey. These ants also developed shorter mandibles, defining how they hunt.

Delving into the decline stage

The taxon cycle hypothesis predicts that over time, as species adapt to increasingly specialized niches, their population size and the range of their habitat declines. These predictions only held true for the Fijian trap-jaw ants in the upland habitats.

The team found that the populations of upland species of ants had shrunk in numbers over time and had greater genetic differences between populations, suggesting that they were less able to disperse and breed across the Fijian archipelago.

This loss of competitive ability increases the vulnerability of these older, more specialized ants, which are currently threatened by deforestation — a major environmental issue in Fiji. “Because these endemic species only occupy a small geographical area and only have a limited ability to disperse, deforestation can quickly lead to extinction of these species,” said Dr. Liu.

The team now plans to apply their approach, which combines population genomics, phylogenetics and morphological studies, to all ant species on Fiji.

It’s still not clear how closely data from the trap jaw ants aligns with the taxon cycle hypothesis, said Dr. Liu. This study, as well as one published last year that examined the Pheidole genus of Fijian ants, “only provided partial support” for the hypothesis, he said. “More data is needed to determine whether evolution on these islands does follow these predictable stages, or whether it is a more random process that differs each time.”

As part of her PhD at Edith Cowan University in Western Australia, Mandy Richardson conducted the world’s first data-driven study of parenting classes based on the Respectful Approach intervention.

The Respectful Approach, modelled on Resources for Infant Educators (RIE)TM, guides parents to treat young children as capable and independent humans who can flourish if given safe space and freedom from too much adult direction.

Parents were invited to take part in a class for infants or toddlers over six weeks where they observed their children in uninterrupted play in a room with age appropriate toys.

The infants and toddlers were free to investigate their environment and interact with other children while parents sat in the room and watched with a facilitator. After an observation period, each class introduced and discussed a topic related to the Respectful Approach.

At the end of the program, parents reported significantly lower stress levels, with more confidence and a better understanding of their children’s capabilities.

Children make progress when given space and time

Ms Richardson said the Respectful Approach is ultimately about building a trusting, lasting bond with positive communication between parents and children. There is less focus on checklists and achieving milestones, with acknowledgement that each child is different.

“Participants in the study reported worrying less about performance pressure after attending the classes, which let them refocus on their relationship with their children,” she said.

“As parents we tend to go and ‘save’ our children when they start to struggle with something, instead of letting them try to resolve their own challenges. But if the children aren’t looking for help, perhaps they can be left to do their own thing and work it out themselves.”

Ms Richardson explained the Respectful Approach helps to establish good patterns in early years so children learn to build confidence in their abilities and to deal with conflict in emotionally intelligent ways.

“Traditionally early behavioural interventions have predominantly focused on modifying undesirable child behaviours,” Ms Richardson said.

“By building good communication and a close parent-child bond, we can potentially prevent problems occurring in the long term.”

Ms Richardson and her research supervisor Associate Professor Therese O’Sullivan are now expanding the pilot study to track parents and children over three years to determine whether the decline in parental stress levels has a lasting impact and investigate long term outcomes in child development.

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