Top left of image shows a picture of a purplish-grey sea cucumber. Above the cucumber is the word "bio-inspiration." Arrows come from the cucumber to anthropomorphized cartoons of it saying "rigid" at the top with a cartoon sea cucumber standing straight up with spikes and the arrow captioned "soft" pointing down showing a crawling sea cucumber that looks more like a slug. To the right of the cucumber images is a set of three images stacked top to bottom. The top image is of a silver sphere with a zoomed-in atomic diagram with aligned magnetic poles next to it saying "solid state." The middle image shows arrows going up and down next to a snowflake and an artistic rendering of magnetic fields labeled "transition." The bottom image of this section shows a reddish sphere next to a zoomed-in atomic diagram where the magnetic poles are not aligned labeled "liquid state."

Phase Change Materials For Flexible And Strong Robots

February 19, 2023 by Navarre Bartz 21 Comments

Shape shifters have long been the stuff of speculative fiction, but researchers in China have developed a magnetoactive phase transitional matter (MPTM) that makes Odo slipping through an air vent that much more believable.

Soft robots can squeeze into small spaces or change shape as needed, but many of these systems aren’t as strong as their more mechanically rigid siblings. Inspired by the sea cucumber’s ability to manipulate its rigidity, this new MPTM can be inductively heated to a molten state to change shape as well as encapsulate or release materials. The neodymium-iron-boron (NdFeB) microparticles suspended in gallium will then return to solid form once cooled.

Applications in drug delivery, foreign object removal, and smart soldering (video after the break) probably have more real world impact than the LEGO minifig T1000 impersonation, despite how cool that looks. While a pick-and-place can do better soldering work on a factory line, there might be repair situations where a magnetically-controlled solder system could come in handy.

We’ve seen earlier work with liquid robots using gallium and bio-electronic hybrids also portending the squishy future of robotics.

Continue reading “Phase Change Materials For Flexible And Strong Robots” →

Using Phase Change Materials For Energy Storage

March 3, 2021 by Lewin Day 35 Comments

Renewable energy sources are becoming increasingly popular. However, such energy can be wasted if an excess is available when it’s not yet needed. A particularly relevant example is solar power; solar panels provide most of their output during the day, while often a household’s greatest energy use is at night.

One way to get around this problem is by storing excess energy so that it can be used later. The most common way this is done is with large batteries, however, it’s not the only game in town. Phase change materials are proving to be a useful tool to store excess energy and recover it later – storing energy not as electricity, but as heat. Let’s take a look at how the technology works, and some of its most useful applications. Continue reading “Using Phase Change Materials For Energy Storage” →

Thermal Actuators: Hydraulic Motors That Feed On Temperature Changes

August 2, 2018 by Donald Papp 4 Comments

These Fluid Displacement Thermal Actuators designed by [Andrew Benson] are a delightful and profoundly different approach to the Power Harvesting Challenge portion of The Hackaday Prize. While most projects were focused on electrical power, [Andrew]’s design is essentially a mechanical motor that harnesses the fact that Phase Change Materials (PCMs) change volume when they go from liquid to solid or vice-versa; that property is used to provide a useful hydraulic force. In short, it’s a linear actuator that retracts and expands as the PCM freezes or melts. By choosing a material with melting and freezing temperatures that are convenient for the operating environment, an actuator can be reliably operated virtually for free. A proof of concept is the device shown here; a model of a sun-shade that deploys when a certain temperature is reached and retracts when it has cooled.

Sunshade concept, from deployed (top) to retracted (bottom).

Turning temperature changes into useful physical work is the principle behind things like wax motors and even some self-winding clocks, but what [Andrew] has done is devise a useful method of interfacing directly to the fluids; abstracting away the materials themselves in order to provide mechanical power on the other end. These devices, in general, may not be particularly efficient but they have very few moving parts, are astonishingly reliable, and can operate at virtually any scale. [Andrew] has been thinking big, many of his application ideas are architectural in nature.

[Andrew] was inspired to enter his design for The Hackaday Prize, and we’re glad he did because it was selected as one of the finalists in the Power Harvesting Challenge, and will be in the running for the $50,000 Grand Prize. If you also have an idea waiting for an opportunity to shine, now is the time. The Human-Computer Interface Challenge is up next, followed by the Musical Instrument Challenge. All you really need to enter is a documented concept, so sharpen your pencils and give your idea a shot at reaching the next level.