AI News, New robot concept uses responsive materials to swim through water

New robot concept uses responsive materials to swim through water

'Our examples show that we can use structured materials that deform in response to environmental cues, to control and propel robots,' says Daraio, professor of mechanical engineering and applied physics in Caltech's Division of Engineering and Applied Science, and corresponding author of a paper unveiling the robots that appears in the Proceedings of the National Academy of Sciences on May 15.

In the latest iteration of the design, Daraio's team and collaborators were able to link up the polymer elements and switches in such a way to make a four-paddled robot propel itself forward, drop off a small payload (in this case, a token with a Caltech seal emblazoned on it), and then paddle backward.

Next, the team plans to explore ways to redesign the bistable elements so that they are self-resetting when water temperature shifts again -- making them potentially capable of swimming on indefinitely, so long as water temperature keeps fluctuating.

No Motor, No Battery, No Problem

'Our examples show that we can use structured materials that deform in response to environmental cues, to control and propel robots,' says Daraio, professor of mechanical engineering and applied physics in Caltech's Division of Engineering and Applied Science, and corresponding author of a paper unveiling the robots that appears in the Proceedings of the National Academy of Sciences on May 15.

In the latest iteration of the design, Daraio's team and collaborators were able to link up the polymer elements and switches in such a way to make a four-paddled robot propel itself forward, drop off a small payload (in this case, a token with a Caltech seal emblazoned on it), and then paddle backward.  'Combining simple motions together, we were able to embed programming into the material to carry out a sequence of complex behaviors,' says Caltech postdoctoral scholar Osama R.

Next, the team plans to explore ways to redesign the bistable elements so that they are self-resetting when water temperature shifts again—making them potentially capable of swimming on indefinitely, so long as water temperature keeps fluctuating.

Motorless swimming robot uses 3D printed shape memory polymers to propel itself in water

In a proof-of-concept study, researchers from ETH Zurich and Caltech in Pasadena, CA have demonstrated a new propulsion system for motorless swimming robots.

Unlike traditional aquatic mechanisms which rely on propellants or engines to move in water, the swimming robots—made entirely from 3D printed parts—use fluctuations in water temperature to propel themselves.

recent study published in the journal PNAS details how the researchers, led by ETH Professor Kristina Shea, created a small (7.5 cm) mini-submarine with 3D printed paddles that could showcase this propulsion technique.

As the ETH Zurich team demonstrates in a video, a 3D printed mini-submarine equipped with multiple actuators is capable of paddling forward once, dropping its cargo (a small coin, in this case) and paddling backwards to its starting position.

The varied timing of the actuators was accomplished by tweaking the geometry of the 3D printed polymer “muscles.” For example, because thinner polymer strips heat up faster in warm water, they have a faster response than thicker ones.

Soft, 3D-Printable Robot Exploits Temperature Changes in Water to Self-Propel

Imagine fleets of compact, self-propelling robots quietly making their way through the world’s oceans, surveilling marine life and monitoring conditions, each one moving without a power supply or even an engine.

It may sound like science fiction, but thanks to a team of researchers from ETH Zurich and Caltech led by Professor Kristina Shea, this new concept for self-propelling, swimming robots that exploit in-water temperature fluctuations to move, has now undergone a successful proof-of-concept study.

“We had already developed 4D printed deployable structures that use the combination of shape memory polymer strips and tunable, bi-stable joints to reconfigure themselves from flat structures into different forms,” explains Professor Shea.

“Our colleagues at Caltech were interested in how to apply this to create an untethered, propulsion device, i.e., a swimming submarine or robot.” In the study, the team developed and fabricated a 7.5-centimeter mini-submarine using a multi-material 3D printer.

“Most thermosetting polymers (i.e., irreversibly cured plastic from a liquid resin via heat or light) exhibit this behavior.” Users can “program” the SMP to morph from its permanent shape into a second shape when it is heated.

vehicle that doesn’t need a power source would be revolutionary for exploring the deep sea, in part because the need to go back to a ship for more power is such a limiting factor.

“The main takeaway from our work is that we have developed a new and promising means of propulsion that is fully 3D printed, tunable, and works without an external power source.” Top image: Visualization of a simple mini-submarine with two paddles.

3D Printed Swimming Soft Robot Uses Shape Memory Polymers to Paddle Forwards and Backwards

In November, researchers from the Swiss Federal Institute of Technology Zurich (ETH Zurich) published a study that explained how shape memory polymers can be the catalyst for making adaptable materials that will return to their original shape once heated, which we’ve seen before.

The team used 3D printing, programmable design, and thermoviscoelastic meta-materials in the study, and Professor Kristina Shea, along with her doctoral student Tian (Tim) Chen, developed 3D printable shape memory polymer strips for the experiment.

Professor Shea explained, “The main takeaway from our work is that we have developed a new and promising means of propulsion that is fully 3D printed, tuneable and works without an external power source.”

The team’s soft robotics design principle is a material-based approach that can swim untethered, and complete pre-programmed tasks, like deliver cargo and follow specific routes, without any electronics, power sources, or controllers on board.

If the water the mini-sub is floating in is heated, the expanding muscles cause the bistable element to snap, which triggers a paddle stroke. Each actuating element of the mini-sub can complete one paddle stroke before a necessary manual reprogramming, though in the future the researchers believe they can 3D print complex swimming robots that have several actuators.

The team’s current 3D printed robot can paddle forward in one stroke, release a coin, and return to its starting point with a stroke in the opposite direction, and it does all of this just by sensing temperature changes in the water.

Motorless Self-Propelled Swimming Robot by Caltech & ETH Zurich

Engineers at Caltech and ETH Zurich have developed robots capable of self-propulsion without using any motors, servos, or power supply. Instead, these ...