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takyon writes:

Researchers at the University of Colorado in Boulder have combined aspects of pneumatic actuators and dielectric elastomer actuators to create "soft muscles" for robots:

Two soft muscle technologies have jumped to the fore: pneumatic actuators, which pump gases or liquids into soft pouches to create particular movements, and devices called dielectric elastomer actuators, which apply an electric field across an insulating flexible plastic to make it deform with a particular movement. Pneumatic actuators are both powerful and easy to make, but pumps can be bulky and moving gases and fluids around can be slow. Dielectric elastomer actuators are fast and energy efficient. But they often fail catastrophically when a bolt of electricity blasts through the plastic.

Now, researchers led by Christoph Keplinger, a physicist at the University of Colorado in Boulder, have married the best of both technologies, creating soft musclelike actuators that use electricity to drive the movement of liquids inside small pouches. The design is simple. The actuators start with small plastic pouches that contain an insulating liquid, such as regular canola oil from the supermarket. When researchers apply a voltage between electrodes placed on both sides of the pouch, they are drawn together, squeezing the liquid and causing it to flow to nearby regions. The upshot is that the actuator changes shape, and whatever is connected to it moves.

Keplinger and his colleagues report today in a pair of papers in Science and Science Robotics that they created three soft muscle designs that contract with the precision and force of mammalian skeletal muscles. In their Science paper, Keplinger's team showed that a series of doughnut-shaped actuators had the dexterity to enable a robotic gripper to pick up and hold a raspberry [DOI: 10.1126/science.aao6139] [DX]. They also showed that if a bolt of electricity did arc through the insulating liquid between the electrodes, any "damage" was instantly repaired when the arcing stopped, and new liquid flowed into the region. And in Science Robotics, Keplinger's team reports creating two other muscle designs that contract linearly, much like a human bicep, enabling them to lift far more than their own weight at a rapid repetition rate [open, DOI: 10.1126/scirobotics.aar3276] [DX].

Also at Boulder Daily Camera.

Original Submission

upstart writes:

Submitted via IRC for takyon

Rubbery figures: scientists create an entirely soft robot

US researchers have really put the "soft" into "soft robot". They've built one out of nothing but rubber and air.

There aren't even any conventional electronics. Silicone tubing and pressurised air do that job. According to Harvard University's Daniel Preston, the invention could allow operators to "replicate any behaviour found on any electronic computer".

In the case of the bobbing fish-like robot Preston and colleagues created, an environmental pressure sensor determines what action to take.

The soft valves are programmed to react to different air pressures. The robot dives when the circuit senses low pressure at the top of the tank and surfaces when it senses high pressure at depth. It can also rise up on command if someone pushes an external soft button.

In other words, says Preston, it relies exclusively on soft digital logic – and that's a first.

The how and why are explained in a paper published in the journal PNAS.

Original Submission

"upstart" writes:

Submitted via IRC for Bytram

A soft robotic insect that survives being flattened by a fly swatter

Researchers at EPFL's School of Engineering have developed a soft robotic insect, propelled at 3 cm per second by artificial muscles.

The team developed two versions of this soft robot, dubbed DEAnsect. The first, tethered using ultra-thin wires, is exceptionally robust. It can be folded, hit with a fly swatter or squashed by a shoe without impacting its ability to move. The second is an untethered model that is fully wireless and autonomous, weighing less than 1 gram and carrying its battery and all electronic components on its back. This intelligent insect is equipped with a microcontroller for a brain and photodiodes as eyes, allowing it to recognize black and white patterns, enabling DEAnsect to follow any line drawn on the ground.

DEAnsect was developed by a team at EPFL's Soft Transducers Laboratory (LMTS), working with the Integrated Actuators Laboratory (LAI) and colleagues from the University of Cergy-Pontoise, France. The research was published in Science Robotics.

DEAnsect is equipped with dielectric elastomer actuators (DEAs), a type of hair-thin artificial muscle that propels it forward through vibrations. These DEAs are the main reason why the insect is so light and quick. They also enable it to move over different types of terrain, including undulating surfaces.

An autonomous untethered fast soft robotic insect driven by low-voltage dielectric elastomer actuators [$], Science Robotics (DOI: 10.1126/scirobotics.aaz6451)

Original Submission

Phoenix666 writes:

New stretchable, self-healing and illuminating electronic material for wearables and soft robots:

Imagine a flexible digital screen that heals itself when it cracks, or a light-emitting robot that locates survivors in dark, dangerous environments or carries out farming and space exploration tasks. A novel material developed by a team of NUS researchers could turn these ideas into reality.

The new stretchable material, when used in light-emitting capacitor devices, enables highly visible illumination at much lower operating voltages, and is also resilient to damage due to its self-healing properties.

This innovation, called the HELIOS (which stands for Healable, Low-field Illuminating Optoelectronic Stretchable) device, was achieved by Assistant Professor Benjamin Tee and his team from the NUS Institute for Health Innovation & Technology and NUS Materials Science and Engineering.

[...] Unlike existing stretchable light-emitting capacitors, HELIOS enabled devices can turn on at voltages that are four times lower, and achieve illumination that is more than 20 times brighter. It also achieved an illumination of 1460 cd/m² at 2.5 V/µm, the brightest attained by stretchable light-emitting capacitors to date, and is now comparable to the brightness of mobile phone screens. Due to the low power consumption, HELIOS can achieve a longer operating lifetime, be utilized safely in human-machine interfaces, and be powered wirelessly to improve portability.

The researchers say the material promises durability and efficiency.

Journal Reference
Yu Jun Tan, Hareesh Godaba, Ge Chen, et al. A transparent, self-healing and high- κ dielectric for low-field-emission stretchable optoelectronics, Nature Materials (DOI: 10.1038/s41563-019-0548-4)

Original Submission

upstart writes:

Scientists unveil bionic robo-fish to remove microplastics from seas:

Scientists have designed a tiny robot-fish that is programmed to remove microplastics from seas and oceans by swimming around and adsorbing them on its soft, flexible, self-healing body.

Microplastics are the billions of tiny plastic particles which fragment from the bigger plastic things used every day such as water bottles, car tyres and synthetic T-shirts. They are one of the 21st century's biggest environmental problems because once they are dispersed into the environment through the breakdown of larger plastics they are very hard to get rid of, making their way into drinking water, produce, and food, harming the environment and animal and human health.

[...] The robo-fish is just 13mm long, and thanks to a light laser system in its tail, swims and flaps around at almost 30mm a second, similar to the speed at which plankton drift around in moving water.

The researchers created the robot from materials inspired by elements that thrive in the sea: mother-of-pearl, also known as nacre, which is the interior covering of clam shells. The team created a material similar to nacre by layering various microscopic sheets of molecules according to nacre's specific chemical gradient.

This made them a robo-fish that is stretchy, flexible to twist, and even able to pull up to 5kg in weight, according to the study. Most importantly, the bionic fish can adsorb nearby free-floating bits of microplastics because the organic dyes, antibiotics, and heavy metals in the microplastics have strong chemical bonds and electrostatic interactions with the fish's materials. That makes them cling on to its surface, so the fish can collect and remove microplastics from the water. "After the robot collects the microplastics in the water, the researchers can further analyse the composition and physiological toxicity of the microplastics," said Wang.