Build Your Own Sensor Skin

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]

Paper Thin Conductors

Swedish scientists have created something they call power paper by using nanocellulose and a conductive polymer. The paper is highly conductive and has applications in supercapacitor technology and printed electronics.

The paper, technically called NFC-PEDOT paper, combines high conductivity and compatibility with conventional paper handling machines that could lead to less expensive manufacturing. The team used the material to create supercapacitors (up to 2F) as well as FET-like transistors known as OECTs (Organic Electrochemical Transistors).

Admittedly, the supercapacitor prototype didn’t look very practical (as they dunked it in a beaker full of potassium chloride). The black-colored paper is relatively conductive (42,000 S/m at 20 degrees C), at least for a paper. As a point of reference, silicon is about 1,000 S/m and iron conducts at about 10,000,000 S/m.

What can we do with NFC-PEDOT? Time will tell. We couldn’t help but wonder, however, if paper-based 3D printing couldn’t be adapted to use paper as an insulator or dielectric, foil as a conductor, and something like this material to build resistive elements. After all, we’ve seen something similar using foil and paper before.

Combination Lock Made Out of Paper

Most projects we feature are of the metal/wire/wood variety, but there is an entire community devoting to making very interesting and intricate things out of paper. Imgur user [Criand] has been hard at work on his own project made entirely out of paper, a combination lock that can hold a secret message (reddit post).

The motivation for the project was as a present for a significant other, wherein a message is hidden within a cryptex-like device and secured with a combination that is of significance to both of them. This is similar to how a combination bike lock works as well, where a series of tumblers lines up to allow a notched shaft to pass through. The only difference here is that the tiny parts that make up the lock are made out of paper instead of steel.

This project could also be used to gain a greater understanding of lock design and locksport, if you’ve ever been curious as to how this particular type of lock works, although this particular one could easily be defeated by a pair of scissors (but it could easily cover rock). If papercraft is more of your style though, we’ve also seen entire gyroscopes and strandbeests made of paper!

Dampen Workshop Noise with Paper Pulp and Kool-Aid — OH YEAH!

noise dampener

If you’re fortunate enough to have a garage and a workshop, you probably also have neighbors. The truly blessed must work within the confines of an HOA that restricts noise, porch couches, and most types of fun. [Mike] is among the truly blessed, and when he decided to design a cabinet for his CNC equipment, he took noise dampening into consideration.

[Mike]’s design isn’t a blanket noise dampener; it’s specifically designed for the high-pitch symphony of his router, compressor, and vacuum. He also sought to avoid vibrating the cabinet. To achieve this, the sound-dampening panels are hung on eye hooks with a 1/2″ gap between them and the frame. The backer boards are cut from 3/4″ plywood. [Mike] considered using cement board, but thought it might be overkill since he plants to shell the cabinet in a layer of 3/4″ plywood.

The deadening material is paper pulp made from various shredded papers. After soaking the shreds in water and blending the mixture to an oatmeal consistency, he drained most of the water through a cloth bag. Then he added just enough wood glue to hold the pulpy goo together. The tropical punch Kool-Aid powder isn’t just for looks; it provides visual confirmation of even glue distribution.

[Mike] made some tape walls around the edge of his backer boards to hold the mixture in place and painted on some wood glue to hold the pulp. He spread the tropical concoction to 1/2″ thickness with a tiling trowel to avoid compressing it. The peaks and valleys help scatter any sound that isn’t absorbed. Pudding awaits you after the jump.

Continue reading “Dampen Workshop Noise with Paper Pulp and Kool-Aid — OH YEAH!”

Roboartist Draws What It Sees


The perfect balance of simplicity and complexity have been struck with this automated artist. The Roboartist is a vector drawing robot project which [Niazangels], [Maxarjun], and [Ashwin] have been documenting for the last few days. The killer feature of the build is the ability to process what is seen through a webcam so that it may be sketched as ink on paper by the robotic arm.

The arm itself has four stages, and as you can see in the video below, remarkably little slop. The remaining slight wiggle is just enough to make the images seem as if they were not printed to perfection, and we like that effect!

Above is a still of Roboartist working on a portrait of [Heath Ledger] in his role as Joker from The Dark Knight. The image import feature was used for this. It runs a tweaked version of the Canny Edge Detector to determine where the pen strokes go. This is an alternative to capturing the subject through the webcam. For now MATLAB is part of the software chain, but future work seeks to upgrade to more Open Source tools. The hardware itself uses an Arduino Mega to take input via USB or Bluetooth and drives the quartet of servo motors accordingly.

Continue reading “Roboartist Draws What It Sees”

An elegant timepiece from paper and a fistful of servos


Segments rise from a sheer white surface to reveal the time in this papercraft digital / analog clock build by [Jacky Mok].

New York-based designer [Alvin Aronson] is responsible for the original, titled “D/A Clock,” which he built as a student at RISD using Corian instead of paper. [Aronson]’s design is also massive in comparison. It measures one meter wide by a half meter tall. Without access to either a 3D printer or to a laser cutter, [Jacky] instead reduces the scale of his interpretation and relies on cardstock as the primary construction material. His experience with papercraft typography leads to a design that anyone with an Exacto knife and a slice of patience should find manageable. [Jacky] ignores the Exacto option, however, and cuts his pieces with a tool we saw earlier this year: the Silhouette Portrait.

The clock’s electronics include an Arduino Uno, a servo motor controller, twenty-eight servos and an RTC breakout board that handles timekeeping. Each servo drives its own segment by sliding a paperclip forward or backward inside a small, hollow aluminum rod. Though we’re still holding out for a video of the finished papercraft build, you can watch a video of Aronson’s original clock after the break and see what inspired [Jacky’s] design.

Need another clock to envy? Last month’s build by [ebrithil] uses twenty-two servos to individually spin the segments. If you prefer that your clocks light up, [Aaron’s] o-scope transformation has you covered.

Continue reading “An elegant timepiece from paper and a fistful of servos”

Draw your own vinyl beats


The Dyskograf lets you make music with a magic marker. The musical installation looks much like a turntable for playing vinyl records. But instead of a spiraling groove containing the sounds, this uses marks on a paper disk to play sound samples.

You can see the light outline of several tracks on the paper disc shown above. By adding black marks the optical input of the Dyskograf knows when to start and end each sound. This is best illustrated in the video demonstration after the break.

The marker-based setup makes a lot of sense, and we think it would be perfect if the disc was a dry-erase board. It certainly makes it a lot easier to lay down new beats than this other optical turntable which required holes to be drilled in a vinyl record to play the sounds. While we’re on the topic you may also find this coin-based turntable sequencer of interest.

Continue reading “Draw your own vinyl beats”