A few years ago, Jasmine Lu was just starting her PhD program in computer science at the University of Chicago. She worked in a lab that integrated devices with the human body.
And she knew she wanted to try and incorporate a living organism into a device. She played around with plants, mushrooms, algae — but they were too picky. Then she discovered a not-so-picky bright yellow blob: slime mold.
The slime mold grew on everything Jasmine tested it on: wires, tubes, random pieces of plastic. And she learned it could do something amazing: conduct electricity.
So Jasmine designed a smartwatch using the slime mold as a “living wire.” The only catch? It needed to be fed and watered to work.
It got Jasmine wondering, what would happen if our devices were alive? If we needed to feed them to make them work? Would it change the way people care about these pieces of plastic and metal we’re so quick to replace every few years?
Credits:
Producer: Ellie Katz
Editor: Morgan Springer
Additional Editing: Dan Wanschura, Claire Keenan-Kurgan, Ruth Abramovitz
Host: Dan Wanschura
Music: Blue Dot Sessions
Transcript:
JASMINE LU: OK, so this is the first room of our lab.
DAN WANSCHURA, HOST: Jasmine Lu is in a lab that feels like fast-forwarding in time: like a super high-tech woodshop mixed with an Apple store. It’s at the University of Chicago. There’s a whiteboard wall completely covered in all these different equations.
LU: We have, like, an array of 3D printers. These are resin printers. This is a laser cutter. There's machine tools.
WANSCHURA: Jasmine Lu is a PhD student here. She’s a computer science researcher, and she’s showing our reporter Ellie Katz around — showing her all these devices that integrate with the human body.
ELLIE KATZ: This place is so mad scientist.
LU: It is.
KATZ: Pedro, who runs the lab, has, like, very big hair. He gives very mad scientist vibes.
WANSCHURA: One of Jasmine’s projects is also pretty mad scientist. She pulls out a little box and opens it up. It’s a smart watch. It’s a chunky, white, square, made out of 3D-printed plastic.
LU: It has all, like the components you would find in like your average smart watch. So it has a screen. It has these buttons. … There's also a heart rate sensor.
WANSCHURA: It’s got a battery and a strap for your wrist. But then there’s something most smart watches don’t have: Underneath the bulky white part with the screen, there’s a small clear container about an inch long.
Now in it, there’s these two circular wells, and a thin channel connecting them.
LU: So we designed this little container for the purposes of this watch. In this well, there's dried slime mold.
WANSCHURA: Slime mold: this single-celled, living organism. Right now it just looks like a speck of dried mustard. But with a little food and water, that speck will grow in its well and then spread through the channel into the other well. And then it does something crazy: conducts electricity. And that’s what makes the watch work. It just needs a little snack.
LU: Do you want to give the slime mold water?
KATZ: Yeah, that sounds great.
LU: It's not anything very hard. So I'm just lifting the lid, and here's your little droplet with water.
KATZ: So that's all it needs — it's gonna come back to life now?
LU: Yes!
KATZ: Wow.
WANSCHURA: This is Points North, a podcast about the land, water and inhabitants of the Great Lakes. I’m Dan Wanschura. Today, Jasmine tries to find out: What would happen if our devices were alive? If we needed to feed them to make them work? Would it change the way we feel about them? Ellie Katz takes it from here.
ELLIE KATZ, BYLINE: Jasmine Lu started working in this mad scientist lab in 2019. OK, it’s not actually a mad scientist lab. It’s called the Human Computer Integration Lab at the University of Chicago, on the south side just 15 minutes from Lake Michigan. Jasmine needed a PhD project of her own. And she got really interested in something called biohybrid devices.
LU: Devices that are working with different organisms, like bacterias or dinoflagellates, or just like other organisms and being like, ‘How could they fit into computing?’
KATZ: Biohybrid devices are basically this combo — this marriage between mechanical bits and bobs and biological bits and bobs. Instead of everything in the device being man made, it incorporates living cells or tissues. Maybe that sounds a little cyborg-y — and it is. But it’s also really cool. Like, imagine a prosthetic hand that’s really dextrous because it uses actual muscle tissue along with all that plastic and metal.
Jasmine was really into these kinds of ideas, and she wanted to build her own biohybrid device. So, she turned her apartment into a laboratory, and started testing out different organisms. She had no idea what device she was gonna invent, but she knew one thing: it needed to survive easily.
LU: So I played around with algae. I grew some mushrooms. I grew plants.
KATZ: These weren’t gonna cut it. They were too picky. And then Jasmine came across something perfect. This not-so-picky, easy to find, bright yellow blob.
LU: Physarum polycephalum.
KATZ: Physarum polycephalum. It’s not like some rare thing. You might see it growing on a rotten tree somewhere. It’s a species of slime mold, which actually isn’t a mold at all. It’s an amoeba. We’re talking high school biology amoeba — those single-celled organisms. This amoeba, the slime mold, is just weird but amazing. It’s somewhere between a liquid and a solid. And it has these tubes – they almost look like veins – that stretch out as it forages around for food. That’s how it grows.
LU: So I started growing them on wires. I started growing them in tubes. I grew them in 3D prints of just random shapes and sizes.
KATZ: The slime grew in these beautiful patterns — almost like a river with all its branching streams but yellow.
LU: I was, like, surprised a lot. They're so resilient. Especially in the early stage where I was like, ‘Let's grow it on everything and see if it'll be OK.’ Like, it grew on everything. It just needed oats and water.
KATZ: And because it grew on everything, Jasmine knew it could survive inside a device. But this experiment wasn’t just about growing some cool looking mold. It actually needed to do something. But what was that? That’s when she found research that said slime mold could conduct electricity.
KATZ: It can do that because it has these jelly-like tubes — those things that look like veins. Fluid moves through those veins and electrical currents can hitch a ride. That was it: Jasmine was sold.
LU: I was like, ‘I have to put this in a device and actually make it a functional part of the device.’
KATZ: She wanted the device to be simple, wearable and easy to use. So the idea of a basic smart watch was born.
LU: And so I created, like, a little cardboard wristlet with, like, a little slime mold growing across.
KATZ: And then, for almost a year, Jasmine worked on making the watch a reality. She tinkered with all the electronics and circuits. She printed more than a dozen variations, trying over and over again to get the pieces all right. And the whole time, there was one thing that kept her going.
LU: I was excited, I think. I don't know— I have to say this was a really fun project, I think because like, even when, like maybe the electronics or the mechanical bits of this weren't working, like, growing the slime mold was always fun, and the prospect of sharing my slime mold was fun.
KATZ: At the end of 2021, Jasmine finally had it. A finished prototype. That chunky, white watch with the clear plastic case at the bottom where the slime mold went. So she had this device made partially of a living organism. It needed to be fed and watered to work. And because Jasmine’s a curious inventor, she wanted to know.
LU: Would this caretaking interaction that we embedded in this device design have any effect on how people felt about this device, the living organism?
KATZ: In other words: Would feeding the slime mold watch make someone care about their device more? It was an idea she wanted to test out. She just needed some willing participants.
KATZ: Riss Lawrence works in the same futuristic building Jasmine’s lab is in, in the media arts and design section. And Riss is artsy. She’s covered in tattoos of plants, birds, her cats and also of cute characters from video games she loves. So, when a message popped up asking for volunteers for a study about slime pets, Riss was immediately in.
RISS LAWRENCE: Part of it attracted me because I grew up playing a lot of games where you care for a virtual pet of some kind. So, was a huge fan of Nintendogs, Tamagotchis. So, the idea of caring for a little slime just sounded really cute.
KATZ: Riss met up with Jasmine to get her watch.
LAWRENCE: The slime was dried up. So, it was like yellow, and just really small and kind of skrunkly.
KATZ: So you weren't like, ‘Oh, I'm kind of surprised this looks like a booger.’ You were like, ‘Oh, this is really cute.’ And predisposed to like, be excited about it.
LAWRENCE: Yeah, I don't know what that says about me.
KATZ: Phase one of the experiment was making the dry slime mold grow, so that it would travel through the plastic channel and create a wire. Basically, Riss needed to bring it back to life.
LAWRENCE: So, every day, you would take the pipette and you would put some water and, like, a little bit of oats, and feed your little slime. And so it was really cool, because you could see how your care was impacting the slime pretty quickly. … It wasn’t like a long, drawn-out process.
KATZ: Within a day or two, the wire grew. And pretty soon, the screen changed. Instead of saying: “Physarum wire not grown, continue caring.” Riss’s heart rate popped up. She’d wear it around town and to work. And then a few days in, she got COVID. But she still had to take care of the watch.
LAWRENCE: I was drinking water and eating oatmeal a lot that week because my throat hurt so bad. So my wife would come in and feed me water and oats, and then I would feed my slime pet water and oats. And she started calling me her little slime.
KATZ: The routine was this: Water and oats for the slime mold. Water and oats for her. Water and oat for the slime mold. Water and oats for her. And then again and again and again.
LAWRENCE: I was like, ‘It's just me and my slime pet and oatmeal against the world right now,’ because this COVID, the COVID was so rough on me.
KATZ: Riss would even talk to it sometimes.
LAWRENCE: Like, ‘OK, here's your water.’ Like, you know, the same way when I put my food down in front of my cats, I'm like, ‘Okay, here's your food,’ you know.
KATZ: And right when she started to feel better came the next phase of the study:
LAWRENCE: The study literally called it, like, the neglectful phase. We had to let it dry out, you just stopped watering and feeding it. And then pretty quickly it would, the wire would disappear, the slime would kind of become all like crunkly again. It would get pale and shrink.
KATZ: And doing this – purposely neglecting the slime mold – Riss was kind of surprised at how it made her feel.
LAWRENCE: It didn't feel good to watch it dry out, especially as I was getting better, because I was still drinking water and eating oatmeal, but this time, I wasn't feeding the slime. So it was a little weird to be eating my oatmeal in front of the slime and not giving them any — [it] felt a little, probably felt a little weird. And maybe that seems kind of dramatic, but me and the slime really went through it together. So yeah, I definitely felt sad about it.
KATZ: But not like she was gonna cry, not like neglecting your pet. It felt sad in a different way — almost like watching your plant slowly die, and not knowing how to help it. Each hour she didn’t feed it, she could see it drying up, shrinking back to just a little speck. Until it looked the same as when she first got it. She gave it back to Jasmine a few days later.
LAWRENCE: But my wife and my sister and I still talk about the slime sometimes, like it has retained a life past the two weeks that I had it.
KATZ: The nickname “my little slime” stuck. Her wife still calls her that sometimes. After the study ended, Riss did an interview with Jasmine, talking about how it went and how she felt. Riss didn’t really want to keep the watch itself — it was kind of bulky, she’s not really a watch person.
LAWRENCE: I think more so the study made me see how quickly I could bond to something like a slime pet, how quickly I could become attached and talk to it sweetly, how we can forge connections with such things. And then, because I forged a connection with it, it made me want to care for it more.
KATZ: There were four other participants in the study besides Riss and then there was me. Jasmine let me take home a watch, very nicely. I was super excited about it at first. But when I actually started to feed and water it, I was honestly just annoyed. It was one more thing to do, one more thing to take care of, out of a million things to take care of. I was just not interested in the routine of it. But I did it for the story.
Every morning when I ate my cereal, and every night when I got a glass of water for bed, I’d pipe a few droplets into the little well. Watching it turn from dry and brittle to wet and mushy was kind of gross but intriguing — in the same way dissecting something in school is. And then watching the slime mold start to grow its way through the channel to the other well was really cool.
I’d leave the watch at home because it’s pretty clunky. It’s big. It’s not the most practical watch. But at work, I’d find myself thinking about the slime mold — the same way I think about my garden. Like, “Did the rabbits eat more of my beans? Are there bugs on my squash? Did I give the slime mold oats yesterday or the day before that?”
I fed and watered it for two weeks, like in the study. I don’t really wanna keep it — I have my own watch. And I won’t miss it once it’s gone. But making a watch people would want to buy was never the goal for Jasmine. This wasn’t some big, statistically significant study. It didn’t set out to prove a scientific theory. It was a thought experiment.
LU: I mean, when I ran the study, I was like, ‘I hope they enjoy it.’ But I think a lot of people found a lot of different opportunities to, like, relate a lot to the slime mold.
KATZ: And how did it make you feel to know that that happened?
LU: Cool! I was like, ‘Oh, that's so fun!’ Like, kind of cute and unique interactions that weren't necessarily things that I explicitly designed for, but that resulted because of just this broader idea that, ‘Oh, it's part of a caretaking practice.’
KATZ: So, Jasmine had an answer to her initial question: caretaking for a device had made people care more, at least for her five participants. But like any good scientist, that got Jasmine wondering about another question. Could that caretaking relationship be useful somehow? If people cared more about their devices, would they be as quick to throw them out as soon as upgrades come out or once the battery drains a little quicker than it used to?
LU: What does it take for a device to become more like an heirloom, something that you want to keep around, pass on things like that?
KATZ: Maybe a device like this could help with electronic waste, or e-waste. It’s one of the fastest growing waste streams in the world.
LU: When I talk about all my projects, but especially this one, I kind of liken it to seeds that— obviously they're not, like, the end-all solution, but it's seeds to provoke or think about how to challenge the problem of e-waste differently.
KATZ: Jasmine’s research has moved on from the slime mold watch, but most of her work now is about reducing e-waste. Like she said, the slime mold watch is just a seed of an idea. Or, if you wanna stick to proper slime mold biology, it’s a spore of a new idea.
