finger

13 Articles

A cinematic shot of the resulting prosthetic finger attached to the glove

Missing Finger Gets A Simple Yet Fancy Replacement

March 3, 2023 by 28 Comments

The possibility of a table saw accident is low, but never zero — and [Nerdforge] has lost a finger to this ever-useful but dangerous contraption. For a right-handed person, losing the left hand pinky might not sound like much, but the incident involved some nerve damage as well, making inaccessible a range of everyday motions we take for granted. For instance, holding a smartphone or a pile of small objects without dropping them. As a hacker, [Nerdforge] decided to investigate just how much she could do about it.

On Thingiverse, she’s hit a jackpot: a parametric prosthetic finger project by [Nicholas Brookins], and in no time, printed the first version in resin. The mechanics of the project are impressive in their simplicity — when you close your hand, the finger closes too. Meant to be as simple as possible, this project only requires a wrist mount and some fishing line. From there, what could she improve upon? Aside from some test fits, the new finger could use a better mounting system, it could stand looking better, and of course, it could use some lights.

For a start, [Nerdforge] redesigned the mount so that the finger would instead fasten onto a newly-fingerless glove, with a few plastic parts attached into that. Those plastic parts turned out to be a perfect spot for a CR2032 battery holder and a microswitch, wired up to a piece of LED filament inserted into the tip of the finger. As for the looks, some metal-finish paint was found to work wonders – moving the glove’s exterior from the “printed project” territory into the “futuristic movie prop” area.

The finger turned out to be a resounding success, restoring the ability to hold small objects in ways that the accident made cumbersome. It doesn’t provide much in terms of mechanical strength, but it wasn’t meant to do that. Now, [Nerdforge] has hacked back some of her hand’s features, and we have yet another success story for all the finger-deficient hackers among us. Hacker-built prosthetics have been a staple of Hackaday, with the OpenBionics project in particular being a highlight of 2015 Hackaday Prize — an endearing demonstration of hackers’ resilience.

Continue reading “Missing Finger Gets A Simple Yet Fancy Replacement” →

Adding Brakes To Actuated Fingers

November 8, 2021 by 10 Comments

Building exoskeletons for people is a rapidly growing branch of robotics. Whether it’s improving the natural abilities of humans with added strength or helping those with disabilities, the field has plenty of room for new inventions for the augmentation of humans. One of the latest comes to us from a team out of the University of Chicago who recently demonstrated a method of adding brakes to a robotic glove which gives impressive digital control (PDF warning).

The robotic glove is known as DextrEMS but doesn’t actually move the fingers itself. That is handled by a series of electrodes on the forearm which stimulate the finger muscles using Electrical Muscle Stimulation (EMS), hence the name. The problem with EMS for manipulating fingers is that the precision isn’t that great and it tends to cause oscillations. That’s where the glove comes in: each finger includes a series of ratcheting mechanisms that act as brakes which can position the fingers precisely enough to make intelligible signs in sign language or even play a guitar or piano.

For anyone interested in robotics or exoskeletons, the white paper is worth a read. Adding this level of precision to an exoskeleton that manipulates something as small as the fingers opens up a brave new world of robotics, but if you’re looking for something that operates on the scale of an entire human body, take a look at this full-size strength-multiplying exoskeleton that can help you lift superhuman amounts of weight.

Continue reading “Adding Brakes To Actuated Fingers” →

Dexterity Hand Is A Configurable Prosthetic Hand

December 14, 2018 by 5 Comments

One of the interesting benefits of the 3D printing revolution is the dramatic increase in availability of prosthetics for people with virtually any need. With a little bit of research, a 3D printer, and some trial and error, virtually anyone can build a prototype prosthetic to fit them specifically rather than spend thousands of dollars for one from a medical professional. [Dominick Scalise] is attempting to flesh out this idea with a prosthetic hand that he hopes will be a useful prosthetic in itself, but also a platform for others to build on or take ideas from.

His hand is explained in great detail in a series of videos on YouTube. The idea that sets this prosthetic apart from others, however, is its impressive configurability while not relying on servos or other electronics to control the device. The wearer would use their other hand to set the dexterity hand up for whatever task they need to perform, and then perform that task. Its versatility is thanks to a unique style of locks and tensioners which allow the hand to be positioned in various ways, and then squeezed to operate the hand. It seems like a skilled user can configure the hand rapidly, although they must have a way to squeeze the hand to operate it, or someone will need to develop an interface of some sort for people without needing to squeeze it.

To that end, the files for making your own hand are available on Thingiverse. [Dominick] hopes that his project will spark some collaboration and development, using this hand as a basis for building other low-cost 3D printed prosthetics. There are many good ideas from this project that could translate well into other areas of prosthetics, and putting it all out there will hopefully spur more growth in this area. We’ve already seen similar-looking hands that have different methods of actuation, and both projects could benefit from sharing ideas with each other.

Thanks to [mmemetea] for the tip!

Continue reading “Dexterity Hand Is A Configurable Prosthetic Hand” →

The Battle Between Robot Harmonica And Machine Finger Rages On

December 13, 2018 by 12 Comments

When asking the question “Do humans dream of machines?”, it’s natural to think of the feverish excitement ahead of an iPhone or Playstation launch, followed by lines around the block of enthusiastic campers, eager to get their hands on the latest hardware as soon as is humanly possible. However, it’s also the title of an art piece by [Jonghong Park], and is deserving of further contemplation. (Video after the break.)

The art piece consists of a series of eight tiny harmonicas, which are in turn, played by eight fans, which appear to have been cribbed from a low-power graphics card design. Each harmonica in turn has a microphone fitted, which, when it picks up a loud enough signal, causes an Arduino Nano to actuate a mechanical finger which slows the fan down until the noise stops. It’s the mechanical equivalent of a stern look from a parent to a noisy child. Then, the cycle begins again.

The build is very much of the type we see in the art world – put together as simply as possible, with eight Arduinos running the eight harmonicas, whereas an engineering approach may focus more on efficiency and cost. Between the squeaks from the toy harmonicas and the noise from the servos entrusted to quiet them, the machine makes quite the mechanical racket. [Jonghong] indicates that the piece speaks to the interaction of machine (robot harmonica) and humanity (the finger which quells the noise).

It’s a tidily executed build which would be at home in any modern art gallery. It recalls memories of another such installation, which combines fans and lasers into a musical machine. Continue reading “The Battle Between Robot Harmonica And Machine Finger Rages On” →

Robot Solves Rubik’s Cube With One Hand Tied Behind Its Back

October 3, 2018 by 3 Comments

For all those who have complained about Rubik’s Cube solving robots in the past by dismissing purpose-built rigs that hold the cube in a non-anthropomorphic manner: checkmate.

The video below shows not only that a robot can solve the classic puzzle with mechanical hands, but it can also do it with just one of them – and that with only three fingers. The [Yamakawa] lab at the University of Tokyo built the high-speed manipulator to explore the kinds of fine motions that humans perform without even thinking about them. Their hand, guided by a 500-fps machine vision system, uses two opposing fingers to grip the lower part of the cube while using the other finger to flick the top face of the cube counterclockwise. The entire cube can also be rotated on the vertical axis, or flipped 90° at a time. Piecing these moves together lets the hand solve the cube with impressive speed; extra points for the little, “How’s that, human?” flick at the end.

It might not be the fastest cube solver, or one that’s built right into the cube itself, but there’s something about the dexterity of this hand that we really appreciate.

Continue reading “Robot Solves Rubik’s Cube With One Hand Tied Behind Its Back” →

Want Gesture-Tracking? All You Have To Do Is Lift Your Finger.

May 2, 2017 by 12 Comments

Watching Tony Stark wave his hands to manipulate projected constructs is an ever-approaching reality — at least in terms of gesture-tracking. Lift — a prototype built by a team from UC Irvine and FX Palo Alto Laboratory — is able to track up to ten fingers with 1.7 mm accuracy!

Lift’s gesture-tracking is achieved by using a DLP projector, two Arduino MKR1000s, and a light sensor for each digit. Lift’s design allows it to work on virtually any flat surface; the projected image acts as a grid and work area for the user. As their fingers move across the projected surface, the light sensors feed the information from the image to the Arduinos, which infers the location of each finger and translate it into a digital workspace. Sensors may also be mounted on other objects to add functionality.

So far, the team has used Lift as an input device for drawing, as well as using it to feign gesture controls on a standard laptop screen. The next step would be two or more projectors which would allow Lift to function fully and efficiently in three dimensions and directly interacting with projected media content. Can it also operate wirelessly? Yes. Yes, it can.

While we don’t have Tony Stark’s hologram workstation quite yet, we can still play Tetris, fly drones, and mess around with surgical robots.

Ardu McDuino Plays The Bagpipes

January 10, 2017 by 27 Comments

To “pipe in” the new year, [John] decided to build a bagpipe-playing robot. Unlike other instrument-playing robots that we’ve seen before, this one is somewhat anatomically correct as well. John went the extra mile and 3D printed fingers and hands to play his set of pipes.

The brains of the robot are handled by an Arduino Mega 2560, which drives a set of solenoids through a driver board. The hands themselves are printed from the open source Enabling the Future project which is an organization that 3D prints prosthetic hands for matched recipients, especially people who can’t otherwise afford prosthetics. He had to scale up his hands by 171% to get them to play the pipes correctly, but from there it was a fairly straightforward matter of providing air to the bag (via a human being) and programming the Arduino to play a few songs.

The bagpipe isn’t a particularly common instrument (at least in parts of the world that aren’t Scottish) so it’s interesting to see a robot built to play one. Of course, your music-playing robot might be able to make music with something that’s not generally considered a musical instrument at all. And if none of these suit your needs, you can always build your own purpose-built semi-robotic instrument as well.

Continue reading “Ardu McDuino Plays The Bagpipes” →