Researchers at North Carolina State University have created a soft robot that moves in a distinctly caterpillar-like manner. As detailed in the research paper in Science Advances by [Shuang Wu] and colleagues, the robot they developed consists of a layer of liquid crystalline elastomers (LCE) and polydimethylsiloxane (PDMS) with embedded silver nanowire that acts as a heater.
The LCE is hereby designed as a thermal bimorph actuator, using a distinct thermal expansion coefficient between the LCE and PDMS sides to create a highly controllable deformation and thus motion. Since the nanowire is divided into sections that can be individually heated, the exact deformation can be quite tightly controlled, enabling the crawling motion.
As can be seen in the video below, the motion is fairly rapid and quite efficient, as well as decidedly caterpillar-like. Although the current prototype uses external control wires that supply the current, it might be possible to integrate a power supply and control circuitry in a stand-alone robot. Since the heater works on low voltage (5 V) and relatively little power is required, this would seem to make stand-alone operation eminently possible.
With just a couple of rigid struts attached to the shins of the rear legs, it becomes possible for the robot to lever itself up into a stable standing position, and even shuffle around a bit. Not bad for a couple bolted-on bits with no moving parts!
[Mark Dufour]’s TACO VR project is a sort of robotic platform that mimics an omnidirectional treadmill, and aims to provide a compact and easily transportable way to allow a user to walk naturally in VR.
Unenthusiastic about most solutions for allowing a user to walk in VR, [Mark] took a completely different approach. The result is a robotic platform that fits inside a small area whose sides fold up for transport; when packed up, it resembles a taco. When deployed, the idea is to have two disc-like platforms always stay under a user’s feet, keeping the user in one place while they otherwise walk normally.
LEONARDO, a somewhat tortured name derived from “LEgs ONboARD drOne,” is actually just what it appears to be: a quadcopter with a set of legs. It comes to us from Caltech’s Center for Autonomous Systems and Technologies, and the video below makes it easy to see what kind of advantages a kinematic mash-up like this would offer. LEO combines walking and flying to achieve a kind of locomotion that looks completely alien, kind of a bouncy, tip-toeing step that really looks like someone just learning how to walk in high heels. The upper drone aspect of LEO provides a lot of the stabilization needed for walking; the thrust from the rotors is where that bouncy compliance comes from. But the rotors can also instantly ramp up the thrust so LEO can fly over obstacles, like stairs. It’s also pretty good at slacklining and skateboarding, too.
It’s easy to see how LEO’s multimodal locomotion system solves — or more accurately, avoids — a number of the problems real-world bipedal robots are going to experience. For now, LEO is pretty small — only about 30″ (76 cm) tall. And it’s rather lightly constructed, as one would expect for something that needs to fly occasionally. But it’s easy to see how something like this could be scaled up, at least to a point. And LEO’s stabilization system might be just what its drunk-walking cousin needs.
This unusual 3D printed Rolling Robot by [ebaera] uses two tiny hobby servos for locomotion in an unexpected way. The motors drive the front wheel only indirectly, by moving two articulated arms in a reach-and-retract motion similar to a breaststroke. The arms are joined together at the front, where a ratcheting wheel rests underneath. When the arms extend, the wheel rolls forward freely. When the arms retract, the wheel’s ratchet locks and the rest of the body is pulled forward. It looks as though extending one arm more than the other provides for rudimentary steering.
The parts are all 3D printed but some of them look as though they might be a challenge to print well due to the number of small pieces and overhangs. A short video (embedded below) demonstrates how it all works together; the action starts about 25 seconds in.
Officially dubbed a “Planar Elliptical Runner,” the bot is a test platform for bipedal locomotion from the Institute for Human and Machine Cognition. Taking inspiration from the gait of an ostrich — we think it looks more like a T. rex or velociraptor, but same difference — [Jerry Pratt]’s team at IHMC have built something pretty remarkable. Contrary to all the bipedal and quadrupedal robots we’ve seen, like Boston Dynamics’ Big Dog and PETMAN, which all fairly bristle with sensors and actuators, the PER is very stripped down.
A single motor runs the entire drive chain using linkages that will look familiar to anyone who has taken an elliptical trainer apart, and there’s not a computer or sensor on board. The PER keeps its balance by what the team calls “reactive resilience”: torsion springs between the drive sprocket and cranks automatically modulate the power to both the landing leg and the swing leg to confer stability during a run. The video below shows this well if you single-frame it starting at 2:03; note the variable angles of the crank arms as the robot works through its stride.
The treadmill tests are constrained by a couple of plastic sheets, but the next version will run free. It’s not clear yet how directional control will be achieved, not is it obvious how the PER will be able to stop running and keep its balance. But it’s an interesting advance in locomotion and we look forward to seeing what IHMC’s next trick will be.
If you watch science fiction movies, the robots of the future look like us. The truth is, though, many tasks go better when robots don’t look like us. Sometimes they are unique to a particular job or sometimes it is useful to draw inspiration from something other than a human being. One professor at Johns Hopkins along with some students decided to look at spider crickets as an inspiration for a new breed of jumping robots.