Engineers at the University of California San Diego have come up with a way to build soft robots that are compact, portable and multifunctional without the requirement for compressed air. 

Instead, they’re using a system of tubular actuators made out of heat-sensitive liquid crystal elastomer sheets. Heating elements are placed between two layers of elastomer, which is then rolled up into a cylinder, allowing the tubular digit to bend and contract.

With this novel method, they’ve been able to build a three-jaw gripper, as well as a robot that walks independently with four legs under Arduino control. While the grippers are slow at this point, taking 30 seconds to bend and minutes to return to their original position, the eventual goal is to have them react at the speed of human muscles.

As shown in the video below, Tristan Calderbank is a very talented singer and guitar player, but what’s perhaps most interesting about his performance is the percussion section. Instead of a person (or an entire band) standing beside him, a robotic shaker, tambourine, snare drum and bass drum all play together under MIDI control.

Each device is activated by an HS-311 servo—or two in the case of the snare—powered by an Arduino Uno and MIDI shield. Signals are sent to the Arduino by a laptop running Ableton Live, and servo velocity can be varied to further control sound. 

A write-up on Calderbank’s build process can be found here, including what didn’t work, plus info on sound isolation from the servos. Arduino code is available on GitHub.

YouTuber Oracid1 has developed a unique family of four-legged robots, dubbed “FiveBarQuads.”

The quadrupeds all feature ultrasonic sensing for navigation and a body made out of LEGO components — and as seen in the first video below, his latest (and largest) version is able to navigate quite nicely on its own. It’s even able to traverse a grate and maneuver around a potted plant, though chair legs are understandably a bit tricky.

The robots use an Arduino Uno for control along with a total of 16 micro servos in its shoulders (four each) in order to move the limbs. Two servos are employed to actuate each upper linkage for the legs, which are attached to bottom sections, and finally to the feet portion through a series of joints. This allows for an interesting locomotion capability that could be applicable in a variety of situations.

What has a dozen servos, a camera, and an Arduino Mega for a brain? Nevon Projects’ snake-bot, of course! 

This impressive robot uses a total of 12 servos for locomotion and can travel across a variety of surfaces under the control of Android app, or autonomously via a sensor mounted to a smaller servo on the head.

The snake’s electronics are split up between a head section that houses batteries and the sensor, and a tail bearing electronics including the Arduino. 

The project is available as a kit, or could certainly provide inspiration for your own project if you want to start from scratch. Check it out oscillating across the ground on tiny rollers in the video below, along with a surprising transformation into a square shape at just before the 1:45 mark.

Gray Eldritch (AKA The Technomanc3r) has been working on a robotic hand for some time now, and has settled (so far) on a design with three independent servo-actuated fingers and a thumb. He’s also implemented a wrist assembly to rotate it back and forth, with an Arduino Uno hidden inside for an entirely self-contained gripper unit.

Each of the three fingers is controlled by a single MG996R servo, as is the wrist, while the thumb adds a second SG90 servo to allow it to move on two axes. The fingers are modular, so they can be swapped out as needed, and you even change the thumb position for ambidextrous operation. 

It remains to be seen what Eldritch plans to do with the gripper, but it looks brilliant by itself in the video below.

If you’ve ever seen a delta 3D printer work, you’ve certainly been amazed at the careful coordination of three motors to accurate position a carriage. While impressive in this role, delta robots can be used for much more, from laser engraving, to pick-and-place operations, to automated phone testing, or even playing the piano.

To make these systems a bit more accessible, Doan Hong Trung has developed an open source delta robot — dubbed Delta X — based on an Arduino Mega and a RAMPS 1.4 board that can do all of these jobs and more. 

Details on the modular kit are available here, along with many more clips of it in action. It’s slated to debut on Kickstarter soon, and you can sign up on deltaxrobot.com to be notified when it launches. Design files for the build will be released when successfully funded.

When you want to build a walking robot, the normal route is to individually control each leg with a number of servos or other actuators. Maker Jeremy S. Cook, however, took a different approach with his ‘ClearCrawler,’ using only a pair of motors to power eight legs. These legs are divided up into sets of four on either side of the bot, allowing for differential control similar to a tank.

The leg linkage design is based on Theo Jansen’s Strandbeest mechanism, and a clear head is also implemented with a pair of 8×8 MAX7219 LED matrix eyes. Onboard control is handled by an Arduino Nano and an L298N driver board, while an Uno with a joystick shield serves as the user interface. Radio transmission is via two nRF24L01 modules.

Code for both the transmitter and receiver can be found on GitHub.

As seen in the videos below, Zeus is a metallic humanoid robot capable of moving its head and arms around, featuring a pair of hand grippers that should be quite useful when the time comes. For now, creator Luis appears to be focusing on its vocal skills, with plans to eventually teach it how to walk.

The robot can engage in conversation with its companion, whether it’s answering questions like “What’s your name?” with“My name is Zeus,” or “What’s your favorite movie?” with “I wasn’t that impressed with the special effects, also the plot was not deep.” Zeus even lets Luis know when he “has no idea what to say.”

Zeus’ communication and movement are accomplished through a variety of hardware, including an Arduino Mega and an AAEON UP board, as well as an Intel RealSense Camera SR300 for vision. Luis is also using CMUSphinx for voice recognition, eSpeak for text-to-speech and AIML chatbot for interactive responses.

Perhaps we’ll see this ~1/2-sized humanoid traipsing around on its own in the future, though hopefully its comment about “taking over the world” was just a joke!

Robotic arms can be interesting, as are robots that roll around—especially on a semi-exotic Mecanum wheel setup. Dejan Nedelkovski’s latest How To Mechatronics build, however, combines both into one package.

This project actually starts out in a previous post, where he constructs the moving base with Mecanum wheels, enabling it to slide and rotate in any direction.

In this final(?) stage, he adds a five-axis robot arm mounted on top of its boxy frame, or six-axis if you count the gripper. Either way, the arm uses a total of six servos for actuation, and the base of the bot travels around under the power of four stepper motors. Each motor is controlled by an Arduino Mega, using a custom shield, allowing repeatable movements in any direction. These can be stored and replayed via the robot’s custom Android app as desired.

What if you were to neglect a robot’s mechanical design entirely and instead construct it out of unusual materials like random sticks? Researchers from the University of Tokyo and Preferred Networks have done just that. To accomplish this feat, the engineers first scanned and weighed the branches, then used deep reinforcement learning to teach the new contraption to walk.

The branch-bots were then constructed in the real world using generic servos, and controlled via an Arduino Mega tether setup with a motor driver and a separate power supply.

You can see one of these bots moving around in the video below, though this configuration ironically seems to have more trouble when dropped off at its native forest habitat. Be sure to read more about this research in IEEE Spectrum‘s article here.

This project aims at creating bricolages of robots out of tree branches found at hand. Through the process in which natural objects learn how to walk by themselves, the artwork portrays the perspectives of objects. Unlike the top-down process where functions of mechanical systems are explicitly defined by designers, this project puts an emphasis on the emergence of functions, which is a bottom-up process where found objects seek for the function as a whole.

Images: Azumi Maekawa/University of Tokyo