Speaker 1: We're here in Seattle at the university of Washington here to check out tiny battery free sensors that float in the wind inspired by the humble dandy lion. Let's check it out.
Speaker 2: So if you think about any large open space where you'd want to deploy lots of sensors for precision agriculture applications or temperature sensors, to monitor things like forest fires, environment and climate change type [00:00:30] scenarios, right? What we've done here is figured out a way to automatically disperse them in the wind inspired by nature
Speaker 1: At the nano engineering and sciences building. We got a glimpse of how these dandelion inspired windsurfing sensors can be made into unique shapes, fitted with tiny electronics and dropped from the sky to cover a large area. The process for making these tiny sensors begins with a laser
Speaker 2: Kinda inspired by how you have natural variation between individual seeds. We actually [00:01:00] have a program that can generate different patterns like this. For example, we can generate different types of fill patterns, different diameters and sizes to vary how fast these things are going to fall. So the different designs will spread out to different distances.
Speaker 1: An added challenge in designing the shape of these battery free devices was ensuring that they always land with their solar panels facing up.
Speaker 2: What we noticed is if you have a completely filled in disc of material like this, right, similar to [00:01:30] how you have some natural seeds, uh, like this Elm seed or other leaves that you see what happens is as they fall, they'll repeatedly flip over and you don't know what orientation they're going to land in by comparison. If you look at dandelion seats that have the same bristly sort of structure that allows some air to flow through the center, these are always going to fall in the same upright orientation, kind of like in, in badminton, the badminton shuttlecock will always, you know, turn and orient the same way.
Speaker 1: Once the dandelion shapes have been [00:02:00] cut it's time to add the electronics.
Speaker 2: Our current prototype has a variety of different sensors that we've tested for measuring things like temperature, humidity, pressure you can attach. What's called an accelerometer. That's the same sort of thing that detects motion in your phone, uh, magnetometer to detect magnetic fields. One of the cool things we were able to do with that is, uh, we can actually detect a car is it's driving by the core part of the system is something that you can easily adapt to lots of different applications for people who are building new kinds of sensors. When you're [00:02:30] building things at this scale, you really have to think about every little bit of weight that you're adding. This is our, our whole circuit, all of our electronics. This is a capacitor. This is buffering up. It's storing up a little bit of energy from our solar cells. So if our solar cells aren't providing enough power continuously, we can charge up just a little bit to be able to take a sensor reading and send it out wirelessly.
Speaker 2: The next little circuit that we have here, this makes sure that our system can actually start up, [00:03:00] even when there's very little, little energy available. And then it will trigger our little micro controller here, our computing chip to actually do the operations that we want. The next chip that we have here is a tiny temperature and humidity sensor. We also have a light sensor here. The last chip that we have here, this is a switch, which is what we use for back scatter. And so that's how we're, we're transmitting information from this thing, wirelessly. This whole thing weighs depending on [00:03:30] exactly which, which sensors. We put 30 to 50 milligrams,
Speaker 1: According to Vikram, these dandelion inspired sensors are small and light enough that a drone could carry 1000 of them. We headed outside to see how that might work. Using a consumer drone, converted into a prototype drop system. We saw how the wind naturally disperses these dandy line inspired sensors With the occasional hiccup.
Speaker 3: Oh,
Speaker 2: They're falling out. Yeah. They fell [00:04:00] out
Speaker 1: <laugh> for now. The discs are made of plastic and need to be retrieved by hand, but Viri and his team are also exploring other options.
Speaker 2: One thing that I'm really interested in is, uh, trying to make these, these kinds of electronic devices, uh, more sustainable. Can we build these sorts of systems using biodegradable materials? We could easily make this dis structure out of say paper or something like that.
Speaker 1: Researchers recently put out a paper that describes their progress in trying to build more sustainable electronics, including the building of a functional prototype [00:04:30] mouse that they say is 90% biodegradable by mass. But the team behind these dandelion inspired sensors have more than just sustainability in mind for their next steps.
Speaker 2: The other thing that we're excited about is right now, these, you know, these devices, they always maintain the same shape as they fall. Right. But what if we could change them as they're falling? Can we, um, you know, can we modulate the shape and control where it's going to land? This would also be a really interesting capability and it has lots [00:05:00] of new engineering challenges as well, where, um, beyond just the sensing component, we also have to add some kind of actuator that can, you know, they can actively change the shape as it's moving.