Robotic Touch Using A DIY Squishy Magnetic Pad

September 22, 2024 by Donald Papp 5 Comments

There are a number of ways to give a robotic actuator a sense of touch, but the AnySkin project aims to make it an overall more reliable and practical process. The idea is twofold: create modular grippy “skins” that can be slipped onto actuators, and separate the sensing electronics from the skins themselves. The whole system ends up being quite small, as shown here.

Cast skins can be installed onto bases as easily as slipping a phone case onto a phone.

The skins are cast in whatever shape is called for by using silicone (using an off-the-shelf formulation from Smooth-on) mixed with iron particles. This skin is then slipped onto a base that contains the electronics, but first it is magnetized with a pulse magnetizer. It’s the magnetic field that is at the heart of how the system works.

The base contains five MLX90393 triple-axis magnetometers, each capable of sensing tiny changes in magnetic fields. When the magnetized skin over the base is deformed — no matter how slightly — its magnetic field changes in distinct ways that paint an impressively detailed picture of exactly what is happening at the sensor. As a bonus, slippage of the skin against the sensor (a kind of shearing) can also be distinctly detected with a high degree of accuracy.

The result is a durable and swappable robotic skin that can be cast in whatever shape is needed, itself contains no electronics, and can even be changed without needing to re-calibrate everything. Cameras can also sense touch with a high degree of accuracy, but camera-based sensors put constraints on the size and shape of the end result.

AnySkin builds on another project called ReSkin and in fact uses the same sensor PCB (design files and bill of materials available here) but provides a streamlined process to create swappable skins, and has pre-made models for a variety of different robot arms.

No Fish Left Behind

July 25, 2023 by Bryan Cockfield 25 Comments

For hundreds of years, Icelanders have relied on the ocean for survival. This is perhaps not surprising as it’s an isolated island surrounded by ocean near the Arctic circle. But as the oceans warm and fisheries continue to be harvested unsustainably, Iceland has been looking for a way to make sure that the fish they do catch are put to the fullest use, for obvious things like food and for plenty of other novel uses as well as they work towards using 100% of their catch.

After harvesting fish for food, most amateur fishers will discard around 60% of the fish by weight. Some might use a portion of this waste for fertilizer in a garden, but otherwise it is simply thrown out. But as the 100% Fish Project is learning, there are plenty of uses for these parts of the fish as well. Famously, cod skin has been recently found to work as skin grafts for humans, while the skin from salmon has been made into a leather-type product and the shells of crustaceans like shrimp can be made into medicine. The heads and bones of fish can be dried and made into soups, and other parts of fish can be turned into things like Omega-3 capsules and dog treats.

While we don’t often feature biology-related hacks like this, out-of-the-box thinking like this is an important way to continue to challenge old ideas, leave less of a footprint, improve human lives, and potentially create a profitable enterprise on top of all of that. You might even find that life in the seas can be used for things you never thought possible before, like building logic gates out of crabs.

Thanks to [Ben] for the tip!

Wearable Sensors On Your Skin

November 7, 2020 by Chris Lott 10 Comments

An international team at Penn State led by [Larry Cheng] made a breakthrough in printing sensors directly on skin without heat. The breakthrough here is the development of a room-temperature sintering technique. Typical sintering of copper happens at 300 C, and can be further lowered to 100 C by adding nanoparticles. But even 100 C is too hot, since skin starts to burn at around 40 C.

You can obtain their journal article if you want the details, but basically their technique combines the ingredients in peelable face masks and eggshells. With this printed circuit is applied to the skin, the sintering process only requires a hair dryer on the cool setting, and results can bend and fold without breaking the connections. A hot shower will remove the circuit without damaging the circuit or your skin. [Larry] says the circuits can be recycled.

They are using these sensors to monitor temperature, humidity, blood oxygen levels, and heart performance indicators. They’ve even linked these various on-body sensors with a WiFi network for ease of monitoring. After reading this report, we’re left wondering, if the sensor is directly on your skin, can it be really called wearable?

We’ve written about printable inks before, but for printed circuit board applications. We can’t help but wonder if this technology would help solve some problems inherent in that technology, as well. Thanks to [Qes] for the tip.

3D Printing Skin Or Maybe A Dermal Regenerator

February 15, 2020 by Al Williams 11 Comments

In space — at least on Star Trek — no one can hear you apply a band-aid. That’s too low tech. When a Star Fleet officer gets an ouchie, the real or holographic doctor waves a dermal regenerator over the afflicted area, and new skin magically appears. Science fiction, huh? Maybe not. A group of scientists from Canada recently published a paper on a handheld instrument for depositing “skin precursor sheets” over full-thickness burns. The paper is behind a paywall and if you don’t know how to get it or don’t want to get it, you can see a video from the University of Toronto, below.

Although they use the term 3D printing, the device is more like a paint roller. Several substances merge together in the print head and lay down on the burn in broad stripes.

Continue reading “3D Printing Skin Or Maybe A Dermal Regenerator” →

Tricked-Out Tablet Becomes Workbench Tool

November 28, 2017 by Dan Maloney 23 Comments

The workbench of the typical electronics hobbyist today would probably be largely recognizable by Heathkit builders back in the 60s and 70s. But where the techs and tinkerers of yesteryear would have had a real dead-tree SAMS Photofact schematic spread out on the bench, today you’ll get more use out of a flat-screen display for data sheets and schematics, and this handy shop Frankentablet might be just the thing to build.

Tablets like the older Nexus 9 that [enginoor] used as the basis for this build have a little bit of a form-factor problem because unlike a laptop, a tablet isn’t very good at standing up on its own. To fix that, they found a suitable silicone skin for the Nexus, and with some silicone adhesive began bedazzling the back of the tablet. A bendy tripod intended for phones was added, and with the tablet able to stand on its own they maximized the USB port with a right angle adapter and a hub. Now the tablet has a USB drive, a mouse, and a keyboard, ready for perusing data sheets online. And hackers of a certain age will appreciate the eyeball-enhancing potential of the attached USB microscope.

[enginoor]’s bench tablet is great, but we’ve seen full-fledged bench PCs before too. Take your pick — wall mounted and floating, or built right into the workbench.

Thanks to [ccvi] for the tip.

Simple Game Boy IPhone Mod Is Simple

October 21, 2016 by Richard Baguley 10 Comments

We’ve featured the work of [Modpurist] before, but his latest hack is wonderful in its simplicity. He wanted to create a more authentic Game Boy feel on his iPhone, so he printed out and stuck a skin on the front that makes it look like a Game Boy. Or rather, a Phone Boy, as the form factor is a bit different.

By measuring out the on-screen buttons and using light photo paper, he was able to have buttons on the skin as well: the touch screen still works through it. You can download his printable templates… and the finishing touch is a similar print for the back of the phone to gives that genuine Game Boy feel. Okay, feel is not the right term since the classic d-pad and red buttons are still just capacitive and have no throw. But this is a clever step in a fun direction.

Check out his other hacks while you are at it, including the Game Boy Fridge.

Continue reading “Simple Game Boy IPhone Mod Is Simple” →

Build Your Own Sensor Skin

February 29, 2016 by Dan Maloney 25 Comments

Scientific research, especially in the area of robotics, often leverages cutting-edge technology. Labs filled with the latest measurement and fabrication gear are unleashed on the really tough problems, like how to simulate the exquisite sensing abilities of human skin. One lab doing work in this area has taken a different approach, though, by building multi-functional sensors arrays from paper.

A group from the King Abdullah University of Science and Technology in Saudi Arabia, led by [Muhammad M. Hussain], has published a fascinating paper that’s a tour de force of getting a lot done with nothing. Common household items, like Post-It notes, kitchen sponges, tissue paper, and tin foil, are used to form the basis of what they call “paper skin”. Fabrication techniques – scissors and tape – are ridiculously simple and accessible to anyone who made it through kindergarten.

They do turn to a Circuit Scribe pen for some of their sensors, but even this nod to high technology is well within their stated goal of making it possible for anyone to fabricate sensors at home. The paper goes into great detail about how the sensors are made, how they interact, and how they are interfaced. It’s worth a read to see what you can accomplish with scraps.

For another low-tech paper-based sensor, check out this capacitive touch sensor keyboard.

Thanks for the tip, [Mattias]