Artificial muscle makes soft robots stronger

A new type of artificial muscle allows soft robots to lift nearly 1,000 times their own weight.

Scientists from Harvard University and MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) have created artificial muscles that allow soft robots to lift objects that are up to 1,000 times their own weight, a new study published in the Proceedings of the National Academy of Sciences reports.

Soft robotics has made large strides over the past decade. However, while recent advancements have enabled the machines to bend and flex in new ways, the softer materials typically come with reduced strength.

The new origami-inspired muscles in the study get around that obstacle and could one day lead to much more efficient machines.

“We were very surprised by how strong the actuators [aka, “muscles”] were,” said study co-author Daniela Rus, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science at MIT, according to Phys.org. “We expected they’d have a higher maximum functional weight than ordinary soft robots, but we didn’t expect a thousand-fold increase. It’s like giving these robots superpowers.”

Making muscle-like actuators is one of the largest challenges in engineering. Now that it has been overcome, scientists can potentially build nearly any robot for almost any task.

Each artificial muscle consists of an inner “skeleton” made from materials like metal coil or a sheet of folded plastic surrounded by air or fluid and sealed inside a plastic or textile bag. A vacuum inside the bag causes the muscles to move by forcing the “skin” to collapse onto the skeleton. That tension drives the motion, and allows the device to work without any other external human input. 

In the study, the team created dozens of different muscles with materials ranging from metal springs to packing foam to sheets of plastic. They then experimented with different skeleton shapes to create muscles that can contract down to 10 percent of their original size, lift a flower off the ground, and twist into a coil.

Those experiments showed the muscles can move in many ways, and are able to operate with a high amount of resilience. Not only that, but the technology can generate roughly six times more force per unit area than mammalian skeletal muscle, and is both lightweight and easy to make. A single muscle can be constructed within ten minutes using materials that cost less than $1.

Another important property is that the actuators are highly scalable, meaning they can be constructed at different sizes. That is important because it greatly increases their potential applications. The team believes they could one day be used for a wide variety of tasks, including miniature surgical devices, wearable robotic exoskeletons, transformable architecture, deep-sea manipulators, and large deployable structures for space exploration.

“The possibilities really are limitless,” added Rus, in a statement. “But the very next thing I would like to build with these muscles is an elephant robot with a trunk that can manipulate the world in ways that are as flexible and powerful as you see in real elephants.”

Levitating water droplets could shed light on contaminants

Scientists have found a new way to detect contaminants in water: by using sound waves to levitate water droplets.

A team of researchers used sound waves to levitate water droplets in midair and discovered that the process can help in the detection of harmful heavy metal contaminants such as mercury and lead in water. The new technique could pave the way for instruments that perform on-site monitoring in real-time, which could help combat lead contamination during water crises like the one in Flint, Michigan.

“Despite the large variety of water sensors that offer continual monitoring, detection of multiple heavy metals dissolved in water can only be performed by sending samples off for specialized laboratory analysis,” Victor Contreras, lead author of the study, said in a press release. “Our new technique is one step toward the development of a simpler analysis approach that could be applied on-site and in real time. This type of water analysis could be used by agricultural, pharmaceutical, water purification and other industries to monitor water for contaminants.”

The new approach uses laser induced breakdown spectroscopy (LIBS) to analyze heavy metals in levitating drops of water. Since the levitating droplets can evaporate in a controlled manner, LIBS analysis is easier due to increased mass concentration of contaminants. The approach can detect very low levels of heavy metals such as cadmium, barium, and mercury in a matter of minutes.

Levitation is achieved by using sound waves, which create a force strong enough to act against gravity, leaving the water droplet suspended in midair.

“Acoustic levitation is a simple and inexpensive method to preconcentrate the elements of interest while avoiding contamination from the substrate surface,” Contreras said. “Moreover, it does not require the sample to have any type of electric or magnetic response like some other methods used to achieve levitation.”

The research team is now working to improve the instrumentation of their new technique.

The findings were published in Optics Letters.

NASA makes an engine that defies Newton laws of motion

This theory has been tested time and again and always been proven right.

Newton’s Third Laws of Motion state that, for every action, there is an equal and opposite reaction. This theory has been tested time and again and always been proven right.

However, NASA has finally made an engine that seems to attempt to dislodge the theory, to some extent. The engine was proposed almost 20 years ago, and up to date, it has not been able to make viable.

The engine is made of a cylindrical cone, which is filled with protons similar to microwaves. The energy filled particles bounce around the chamber causing a forward motion.

“Weirdly, the EmDrive doesn’t expel anything at all, and that doesn’t make sense in light of Newton’s third law or another tenet of classical mechanics, the conservation of momentum,” said Michael Greshko from National Geographic. “The long-standing catch is that the EmDrive seemingly defies the laws of classical physics, so even if it’s doing what the team claims, scientists still aren’t sure how the thing works.”

The engine also has no exhaust or by product and in essence can be used infinitely without it being exhausted. The engine is said to be so powerful that it would be able to propel a rocket to Mars in 70 days, almost half the number of days mathematically possible at the moment. With all these properties, it is believed that that the engine is, therefore, able to propel through the void of space.

But a group of scientists insists that they have a working prototype that would make all this possible. The team has formally published their experiment.