PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Miniature auto differential helps tiny aerial robots stay aloft

Microrobots could be used for search and rescue, agriculture, environmental monitoring

Miniature auto differential helps tiny aerial robots stay aloft
2010-09-04
(Press-News.org) CAMBRIDGE, Mass., Sept. 2, 2010 -- Engineers at Harvard University have created a millionth-scale automobile differential to govern the flight of minuscule aerial robots that could someday be used to probe environmental hazards, forest fires, and other places too perilous for people.

Their new approach is the first to passively balance the aerodynamic forces encountered by these miniature flying devices, letting their wings flap asymmetrically in response to gusts of wind, wing damage, and other real-world impediments.

"The drivetrain for an aerial microrobot shares many characteristics with a two-wheel-drive automobile," says lead author Pratheev S. Sreetharan, a graduate student in Harvard's School of Engineering and Applied Sciences. "Both deliver power from a single source to a pair of wheels or wings. But our PARITy differential generates torques up to 10 million times smaller than in a car, is 5 millimeters long, and weighs about one-hundredth of a gram -- a millionth the mass of an automobile differential."

High-performance aerial microrobots, such as those the Harvard scientists describe in the Journal of Mechanical Design, could ultimately be used to investigate areas deemed too dangerous for people. Scientists at institutions including the University of California, Berkeley, University of Delaware, University of Tokyo, and Delft University of Technology in the Netherlands are exploring aerial microrobots as cheap, disposable tools that might someday be deployed in search and rescue operations, agriculture, environmental monitoring, and exploration of hazardous environments.

To fly successfully through unpredictable environments, aerial microrobots -- like insects, nature's nimblest fliers -- have to negotiate conditions that change second-by-second. Insects usually accomplish this by flapping their wings in unison, a process whose kinematic and aerodynamic basis remains poorly understood.

Sreetharan and his co-author, Harvard engineering professor Robert J. Wood, recognized that an aerial microrobot based on an insect need not contain complex electronic feedback loops to precisely control wing position.

"We're not interested so much in the position of the wings as the torque they generate," says Wood, an associate professor of electrical engineering at Harvard. "Our design uses 'mechanical intelligence' to determine the correct wing speed and amplitude to balance the other forces affecting the robot. It can slow down or speed up automatically to correct imbalances."

Sreetharan and Wood found that even when a significant part of an aerial microrobot's wing was removed, the self-correction engendered by their PARITy (Passive Aeromechanical Regulation of Imbalanced Torques) drivetrain allowed the device to remain balanced in flight. Smaller wings simply flapped harder to keep up with the torque generated by an intact wing, reaching speeds of up to 6,600 beats per minute.

The Harvard engineers say their passive approach to regulating the forces generated in flight is preferable to a more active approach involving electronic sensors and computation, which would add weight and complexity to devices intended to remain as small as lightweight as possible. Current-generation aerial microrobots are about the size and weight of many insects, and even make a similar buzzing sound when flying.

"We suspect that similar passive mechanisms exist in nature, in actual insects," Sreetharan says. "We take our inspiration from biology, and from the elegant simplicity that has evolved in so many natural systems."

INFORMATION:

Sreetharan and Wood's work was funded by the National Science Foundation.

[Attachments] See images for this press release:
Miniature auto differential helps tiny aerial robots stay aloft

ELSE PRESS RELEASES FROM THIS DATE:

Dynamic memory mapping delivers additional flexibility to virtual resource management

2010-09-04
The Department of Computer Science and Technology, Peking University, Beijing, China, has shown that a novel dynamic memory mapping (DMM) model brings about additional flexibility to virtual resource management, leading to the feature-adjustable design of a virtual machine monitor (VMM). The study is reported in Issue 53 (June, 2010) of SCIENCE CHINA Information Sciences because of its significant research value. Memory is one of the most frequently accessed components in virtual machine (VM) systems. Because a VM's memory requirement varies according to the running applications, ...

Effect of heat treatment on the superconducting properties of Ag-doped Sr0.6K0.4Fe2As2 compounds

2010-09-04
The Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, and China Research have collaborated to reveal the heat treatment effects on the superconducting properties of Ag-doped Sr0.6K0.4Fe2As2 compounds. Because of its significant research value, the study is reported in issue 7 of SCIENCE CHINA Physics, Mechanics & Astronomy. Previously, our group studied the effect of adding Ag to polycrystalline Sr0.6K0.4Fe2As2 and found that the critical current density Jc and the irreversibility field increase markedly. ...

Image-based modeling of inhomogeneous single-scattering participating media

2010-09-04
The State Key Laboratory of Virtual Reality Technology and Systems, Beihang University in Beijing, has proposed an image based modeling method for inhomogeneous single-scattering participating media whose density fields may contain high frequency details [1]. This work could reduce the difficulty in capturing real-world participating media, which can be applied to 3D games, film production, virtual reality systems, etc. This study is reported in Volume 53 (June, 2010) of the Science China Information Sciences journal because of its significant research value. Realistic ...

Medicinal cannabis review highlights dilemmas facing health care professionals

2010-09-04
Nurses have a responsibility to respect and support patients who use cannabis for medicinal purposes, but must stay within the law and follow professional guidance at all times, according to a research review in the September issue of the Journal of Clinical Nursing. Dr Anita Green and Dr Kay De-Vries studied more than 50 published papers, together with professional and Government guidance documents, official reports and media coverage, from 1996 to 2009. They point out that the fact that the cannabis is usually obtained illegally can have consequences for those who ...

Recipe for water: Just add starlight

Recipe for water: Just add starlight
2010-09-04
ESA's Herschel infrared space observatory has discovered that ultraviolet starlight is the key ingredient for making water in space. It is the only explanation for why a dying star is surrounded by a gigantic cloud of hot water vapour. Every recipe needs a secret ingredient. When astronomers discovered an unexpected cloud of water vapour around the old star IRC+10216 in 2001, they immediately began searching for the source. Stars like IRC+10216 are known as carbon stars and are thought not to make much water. Initially they suspected the star's heat must be evaporating ...

Long term use of oral bisphosphonates may double risk of esophageal cancer

2010-09-04
People who take oral bisphosphonates for bone disease over five years may be doubling their risk of developing oesophageal cancer (cancer of the gullet), according to a new study published on bmj.com today. Oral bisphosphonates are a type of drug used to treat osteoporosis and other bone diseases and are the most commonly recommended treatment for such conditions. Case reports suggest an association between use of oral bisphosphonates for osteoporosis and increased risk of oesophageal cancer. But the evidence is limited, and no adequately large study with information ...

Roll-out of electronic patient records likely to be a long and complex process

2010-09-04
Interim results from the first comprehensive evaluation of the implementation of electronic health records in secondary care in England have found delays and frustration with the system, according to research published on bmj.com today. The authors, led by Professor Aziz Sheikh from The University of Edinburgh (and which included researchers from The London School of Economics and Political Science, The School of Pharmacy and The University of Nottingham), say experiences from the first-wave implementation site "indicate that delivering improved healthcare through nationwide ...

Scientists unwrap DNA packaging to gain insight into cells

2010-09-04
Scientists have built a clearer picture of how lengthy strands of DNA are concertinaed when our cells grow and divide, in a discovery could help explain how cell renewal can go wrong. Scientists have identified thousands of proteins that play a key role in compacting DNA – a crucial process by which DNA is shortened up to 10,000 times to fit inside cells as they split into two. Researchers hope the findings could shed light on what happens when this packaging process fails and cells divide abnormally – which can lead to cancer or cause developing embryos to miscarry. Scientists ...

Bochum's researchers discover proton diode

Bochums researchers discover proton diode
2010-09-04
Biophysicists in Bochum have discovered a diode for protons: just like the electronic component determines the direction of flow of electric current, the "proton diode" ensures that protons can only pass through a cell membrane in one direction. Water molecules play an important role here as active components of the diode. The researchers led by Prof. Dr. Klaus Gerwert (Chair of Biophysics at the RUB) were able to observe this through a combination of molecular biology, X-ray crystallography, time-resolved FTIR spectroscopy and biomolecular simulations. They report in the ...

Head start for migraine sufferers

2010-09-04
For severe migraine sufferers, psychological treatments build on the benefits of drug therapy, according to a new study1 by Elizabeth Seng and Dr. Kenneth Holroyd from Ohio University in the US. Their comparison of the effects of various treatment combinations for severe migraine – drug therapy with or without behavioral management – shows that those patients receiving the behavioral management program alongside drug therapy are significantly more confident in their ability to use behavioral skills to effectively self-manage migraines. And surprisingly, the increase in ...

LAST 30 PRESS RELEASES:

Are lifetimes of big appliances really shrinking?

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

Pinning down the process of West Nile virus transmission

UTA-backed research tackles health challenges across ages

In pancreatic cancer, a race against time

[Press-News.org] Miniature auto differential helps tiny aerial robots stay aloft
Microrobots could be used for search and rescue, agriculture, environmental monitoring