I, for one, welcome our new robot overlords.

Robert Platt from Northwestern has used a new technology created by Edward Adelson from MIT to make a robot that plugs in USBs. This is more difficult than it sounds (unless you’ve had experience with fourth-dimensional USBs, then it’s exactly as difficult as it sounds). If the robot is not pre-programmed, like these on-the-fly USB pluggers, their external sensors must be highly precise—a centimeter off and your drink will get cold without your USB drink warmer. Or worse. Your pet rock may not charge.


In the unspoken scientific agreement to make robots increasingly human, the sensor system relies on vision. One side of the robot’s rubber gripper is coated with metallic paint. The rest of the gripper is surrounded by a translucent box. Each side of the box emits a different-colored light. When the robot grips, the sides light up depending on how the gel inside of the box deformed. By using computer algorithms that monitor the color and intensity of the light, the three-dimensional structure of the gripped surface can be “seen”. This system worked well. The robot was able to find a dangling USB plug, grab it, and plug it into the port.

The more important discovery here is that the robot can insert the USB correctly on the first try. Technology has truly passed our human limitations.

I’m like a rat. I only fly away.

A decade ago, scientists at the University of Florida taught a Petri dish rat brain to fly a flight simulator. They grew a culture of 25,000 rat neurons and, using 60 electrodes, hooked it up to a common desktop computer. At first, the neurons were simply scattered in the dish, but they quickly started to form connections. “You see one extend a process, pull it back, extend it out – and it may do that a couple of times, just sampling who’s next to it, until over time the connectivity starts to establish itself,” Thomas DeMarse, the lead biomedical engineer of the work, described in a ScienceDaily release. When the neural network was joined to the computer, more connections formed as the “brain” learned to control the simulated F-22. Eventually, the “brain” could control the pitch and roll of the aircraft in a variety of conditions, including hurricane-force winds.


Would a Petri dish brain get motion sickness?

According to the release, “As living computers, they may someday be used to fly small unmanned airplanes or handle tasks that are dangerous for humans, such as search-and-rescue missions or bomb damage assessments.” A prescient statement for a time before drones (or at least before the public knew). Who knows, maybe the next generation of war will be fought by rat brains.

(For anyone who doesn’t understand the title of this post, I thought I’d bring back some early 2000s references. Remember this?)

Hemp: Not Just for Granola-Eating Hippies

Hemp is back, man, and more energizing than ever. David Mitlin, then at the University of Alberta and now at Clarkson University, has developed a method for making supercapacitors out of hemp that is not only much cheaper than graphene (the cream of the crop as far as organic conductors go), but also outperformed standard devices by nearly 200%.

In a press release from the American Chemical Society, Mitlin gives the best quote possible on his research: “We’ve pretty much figured out the secret sauce of it. The trick is to really understand the structure of a starter material and to tune how it’s processed to give you what would rightfully be called amazing properties.” Right on.


The American Society of Mechanical Engineers is down with hemp.

To make the supercapacitors, his group heated hemp waste at 180 °C (~350 °F) for a day to get a nice char going, then blasted it at 800 °C (~1470 °F) with a little potassium hydroxide. That final burn turned the char into carbon nanosheets (as so nicely depicted in the above picture from the American Society of Mechanical Engineers). The hemp precursor left a lasting impression on the nanosheets, giving them the unique molecular structure that Mitlin claims is key to his device performance. The sheets were riddled with holes 2–5 nanometers in diameter, making nice paths for charges to move in and out.

Yury Gogotsi, materials scientist at Drexel University, in a comment to Chemical & Engineering News, says that scaling up the process may be difficult (read: costly), what with the high temperatures and day-long heating process.

But that’s just, like, his opinion, man.

John Rogers In The 24th and a Half Century

In the lab of University of Illinois Urbana-Champaign Professor John Rogers, electronics fall apart or, more accurately, dissolve in water. Transient electronics, as they’re called, are designed to be temporary. They have the potential to be implanted in the body, monitor vital signs or fight infection, and slowly dissolve into harmless components. If scaled up to manufacturing levels, these devices have the potential to revolutionize electronics. And his group has been working hard by publishing a lot of papers on the subject.

So I was surprised when I saw a recent report by the Rogers group in Nature Communications on a wholly different class of electronics. (Though maybe I shouldn’t be surprised since Rogers got his Ph.D. under none other than George Whitesides who may be the most diverse chemist of today.) In this new report, he’s using fractal patterns to integrate metal wires into a stretchable substrate. At first I thought, “How the hell is he going to make an infinite recursion wire.” Then I found out that space-filling curves are fractals (thanks Wikipedia). You can think of the patterns like a winning game of Snake, lines packed as close as possible without overlapping. An excited group of mathematicians figured out mathematical functions for different varieties of packing and left us with the below patterns. (Traditionally, the mathematical functions have hard edges, but Rogers has replaced the edges with arcs to improve the mechanics—hard turns create stress points which break easily.)


Different fractal patterns used in the devices.

So wires of different patterns are embedded in a polymer substrate. So what? Well, it turns out interesting mechanical properties arise with the different patterns. These things can stretch. The “stretchability” is well above the 20% necessary to mimic skin. So that’s what they did. Using the Peano layout, they spelled out the word ILLINOIS and mounted it on someone’s actual skin. Then, using a “skin-replica” they took optical and scanning electron microscopy images to prove that the wires conform to the valleys and hills of normal human skin.


The word ILLINOIS was embedded on actual, living skin. Boxes e and f are optical and scanning electron microscopy images on a skin-replica.

“Amazing,” I thought. Wearable electronics may soon be reality. And if this was my work, I would probably stop there, too excited not to publish. But it’s not and a good thing, too. They went on to make actual functioning devices able to heat, sense temperature, and take electrocardiograms (ECGs). They made tiny heart monitors.


And not only that. The devices are compatible with MRIs. Because there are no closed loops in these devices, there aren’t any circulating magnetic currents that may cause signal loss. They’re completely invisible in an MRI scan.

It’s not often that math-inspired work crops up in chemistry (for a hard science, chemists are surprisingly squeamish about math), but when it does it’s always beautiful. It seems that John Rogers has made it his personal mission to advance us to the next level of technology… and into the twenty-fourth and a half century!

“Never give up. Never surrender.”

One of my favorite research projects to follow is Whitesides’ soft robot. Part of his platoon (since he has enough graduate students to call it such) has been developing a mobile robot made purely of polymers. No metal necessary. The body of the robot is divided into air sacs that are pumped full or evacuated to create movement. They’re supposed to resemble starfish, but they look more like army commandos crawling under enemy gates.

By filling the sacs in the right order, the soft robot can slip under a raised barrier.

By filling the sacs in the right order, the soft robot can slip under a barrier, such as your bedroom door at night.

Soft robots are cheap, easy to fabricate, lightweight, and have the advantage of picking up delicate objects, like an egg, without crushing it.


In a new paper in Advanced Functional Materials, the group shows that the robots can resist blunt impacts “better than hard robotic structures (and also most animals of comparable weight and size).” Though I hope they didn’t have a control for that parenthetical joke. The group wanted to quantify exactly how much damage these robots can take. So, in a comically sad fashion they hit their robot with a hammer. If you have access to the paper, check out the Supporting Information for some videos that will make you feel a little bit bad for laughing. Of course, the “hammer test” was in addition to more traditional scientific methods for measuring stress and strain.

You can knock him down, but he'll get right back up.

You can knock him down, but he’ll get right back up.

Since whacking the poor guy with a hammer wasn’t enough, they ran him over with a car. And when that wouldn’t stop him, they ran him over again but this time with a pile glass underneath. Yet, he continued to grip. They proved that these little guys are highly resistant to mechanical stress. Of course, if the glass had managed to poke a hole in one of the sacs the robot would cease to inflate, in effect maiming it, but the polymer they use, an Ecoflex silicone, is fairly puncture resistant.

He's a survivor.

He’s a survivor.

These flexible robots really delight me. They’re not creepy enough to give me chills (Boston Dynamics, I’m looking at you)  and they’re not human enough to make me think of bad sci-fi movies. Well, maybe my science fiction thoughts aren’t totally gone, because, after reading the paper and opening this text editor, I started to type:  I’m glad these guys aren’t sentient… yet.

Be More Negative

It’s going to take more than just reducing our emission of greenhouse gasses to replenish our atmosphere. That’s where negative-emission technologies comes in.

Negative-emission technology requires the net amount of greenhouse gas in the atmosphere to decrease. This doesn’t mean that new technologies will go up into the sky and pull out the bad stuff. Instead, carbon dioxide and other gasses can be sequestered from plants and pulp mills and stuck in the ground. Though this seems like a temporary solution—what happens to that land? So far, sequestering hasn’t been studied in tremendous depth and isn’t used industrially.

It is, however, assumed in almost all scenarios involving less than a 2 ºC temperature rise—that’s when the serious consequences of global warming start.

To bring more research attention to this, Tim Kruger (not @TimKrugerXXX) from the University of Oxford set up a conference, happening this week. Kruger suggests regulating carbon dioxide emissions and making plants pay to clean up their atmospheric trash. I stand fully with that, but I can’t see it actually happening in the US. (Insert joke about Congress being worthless.)

The United Nations’ Intergovernmental Panel on Climate Change is encouraging such geoengineering, but many people find it risky. It would only take one country, maybe even one research group, to mess things up for everyone. With everyone rushing to find a solution before the world boils, it’s likely someone will be hasty. But that doesn’t mean we shouldn’t try. Maybe we need to be negative to get positive results.

Records without the record

I had an idea the other night. My boyfriend has recently gotten into records—yes, they still make records for new music. In the past six months he’s probably bought a hundred records. They’re taking up a lot of room in the living room.

His argument is that the sound quality is better. I didn’t believe him at first, mainly because I didn’t know or care anything about sound quality. Then he put on a band I knew, songs I’ve heard a millions times. I thought I was familiar with every squeak of a finger slide, every sucked in breath—basically all the side noises that come with making music. Then I listened to the record. There was so much going on. Background loops I’ve never heard. Music under the music. He was right, there is no comparison to record quality.

They just take up so much room. They scratch easily. They sell out quickly, and then they get expensive. Hundreds of dollars expensive. I thought of a better way to get record quality without, well, the records.

Imagine you have stimuli-responsive polymer, which is exactly what it sounds like. Now let the stimulus be an electrical pulse and the response be a volume change (it bulks up when you zap it with electricity). This is commonly called a piezoelectric material. Now line the grooves of a traditional record with small squares of electrodes and coat it in the polymer. That’s our new and improved record. You only need one.

Now to get music out of it. Records work by a needle running over little bumps and divots in the spiral grooves, kind of like this road in Lancaster, CA, except in that case the car is the needle. In our system, when you apply an electrical signal to a specific electrode on the imagined record, it would zap the polymer around it and puff up. There’s the bump the needle needs to read music.

All over our record we have electrodes controlled by a computer sending in information on where and how much to electricity to apply (so the position and size of the bump can be controlled). The music file would be stored on a computer in coordinates and electrical strengths (where and how much). The files would be small. Small enough to store all that extra information digital coding cuts out. Small enough for record quality.

In essence, the digital files would be converted to analog. You wouldn’t need a collection of physical records. And they wouldn’t be junking up my living room, Tim.