Richard Bomphrey from the University of London’s Royal Veterinary College talks about how mosquitoes can detect surfaces using the airflow caused by the movement of their own wings … and the autonomous drones he developed to mimic them. Such low-power sensing systems have major potential for future use in safer rotorcraft or drone control systems.
An interview with: Richard Bomphrey
Reference Richard's research:Nakata, T., Phillips, N., Simoes, P., Russell, I., Cheney, J. A., Walker, S. M., & Bomphrey, R. J. (2020). Aerodynamic Imaging by Mosquitoes Inspires a Surface Detector for Autonomous Flying Vehicles. Science, 368(6491), 634-637. https://doi.org/10.1126/science.aaz9634
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[00:08] spk_0: welcome to science pods, where researchers share the stories behind their science.
[00:21] spk_1: In this podcast, we hear from Richard Bomb pre about recent research on mosquito inspired biotechnology to get started, we were curious to hear Richard's story of becoming a researcher. Mm,
[00:41] spk_2: hi, I'm Richard, Bomb free. I'm a professor of comparative biomechanics at the Royal Veterinary College. I work on the biomechanics of animal flight. Whether that's insects or birds, we do a lot of work with birds of prey on. We do a lot of work with insects. Insects are of fundamental interest to me because it's like since I was a kid, I've looked in the garden and noticed that no to insect species lookalike it all, you know, in the same way that Darwin's finches were inspiring to Darwin, it's nice to be ableto look at a group of animals. Andi, try toe pin down exactly what it is, which has caused this great radiation in tow. Endless forms. When I was young, I grew up in in Grantham, in Lincolnshire, which is famous to people. It's the birthplace of Margaret Thatcher. On it, it's also the birthplace of Sir Isaac Newton. In fact, he went to my old school. From there, I read biological scientists at Exeter University on for my third year research project. I got really fascinated in in flight. I was under the tutelage of Robin Wooten, who was a paleobiologist. Andi made his name looking at fossil insects and particularly inspired in me and interest in the Dragonflies, the Dragonflies almost unchanged, certainly in their wing structure since the first insects took to the skies about 350 million years ago. When I got to the end of that project, unfortunately, he was retiring on. I wanted to carry on doing this kind of thing, and so he recommended to me Ph. D position in the zoology department at Oxford University. That was with Professor Adrian Thomas on. He had been working on similar problems from birds tales to insect flight, and he had an opening for a PhD position. And I thought, Well, that sounds fun. If I don't like it, I can always stop on. That's pretty much been my philosophy on my whole career, but I'm still enjoying it, so I haven't stopped.
[02:51] spk_0: Mm hmm. Research studies rarely start out with the questions readily in hand from the science lab to the pub. The paths that researchers take leading up to a study are as unique as the researchers themselves. So we asked, How did this study come about? Mm.
[03:22] spk_2: It was always a sensory project. So we needed to know the aerodynamics because we had a hunch based on a suggestion in a paper quite some time ago, now that they might be using the flow field to sense surfaces, even in the dark. And so that's what this latest paper is about. If you're flying in the dark at light levels below, which the compound I starts to function, how do you know that you're not going to crash into something or how do you land very, very gently on a surface on? We know that mosquitoes do land gently on surfaces, even in the dark. And there's good reason for that. Isn't there? Because if you feel a mosquito land on you quite heavily, then it does not end well for the mosquito onda. Similarly, the females are laying their eggs over water quite frequently, and they do a dipping behavior where they go close to the water surface. But they don't actually touch the water surface because that could spell the end. So we thought, mosquitoes are surrounded in mechanics sensors, so these are not vision sensors. Thes are hairs potentially or the antennae, which respond to the tiniest, angular deflections you can imagine on we thought. Well, when a helicopter flies, that's spinning, disk generates a a down wash, which is why people hold on to their hats when they're getting in tow. Helicopters. We can all visualize that big jet coming down off the rotor blades, and we know also that helicopter pilots very sensitive to the fact that when they're flying close to the ground, it's very difficult. It's one of the harder helicopter tasks taking off the landing because as it's throwing out this downward jet, it creates a higher pressure region, and it's a bit like a bubble or a mound on. The helicopter wants to slide off it, so holding position in a helicopter very close to the ground actually requires quite a lot of concentration. The pilots on the scientific community around the sort of aerodynamics literature are very familiar with the concept of ground effect. But what was new was that we were looking for sensors on the mosquito that they could use to monitor that. In these dark situations, we knew where to look because the antennae of mosquitoes are ridiculously sensitive. That's because many insects have the base of their antennae organs called the Johnston's organ. And these are the receptive cells, which detect deflections of the antenna shaft away from its base position. So our question was very simple. Does that move in a way that is detectable to mosquitoes when they're flying?
[06:18] spk_1: Uh huh. To understand the findings of any research, you have to begin with the methods applied by the researcher. With this in mind, we asked Richard how this study was conducted. We will hear Richards response after this short message. This'll episode is brought to you by thinks share a free to use cloud based platform for storing and sharing your research outputs. Upload your tabular data images, three D scams videos and more to fig share to get credit for all your research. Here again, is Richard bum free?
[07:02] spk_2: We had a plan. Now we said, we think that the mosquitoes can detect this surface by monitoring fluctuations in their own flow that they're generating themselves. But it would be nice to prove that concept on some sort of flying device. So we got one of these palm sized quad copters. It's a toy, really, But it's one of those toys, which has been specifically designed with developers in mind and academics in mind, you can get access to the source code on you can modify it or Hackett to your heart's content. So what we did WAAS put on some sensors, which would monitor changes in the flow field and tell a circuit board, which we added, um, using a sort of expansion capability, that these devices have to illuminate some lights if it thought it was near a surface. Now we didn't use mosquito antennae, although potentially you could. It's a bit of a Frankenstein cyborg solution, but potentially that would work, we thought. Let's take a simpler option. There are many pressure sensors that you can purchase, which are very small and very lightweight. Andi very well suited to be carried on on these little flying machines. So we got an array of those. We knitted them together with some tubes which took the readings of the air pressure right in the places where we knew the flow would change most. And we sent that to the flight controller. And lo and behold, we could detect obstacles in a bio inspired fashion. I like this kind of bio inspiration because what you'll find in the world of biomechanics and biometrics is that there's quite a lot of post hoc justification of things which suddenly, you think Well, actually, that looks a little bit like a on then insert animal here. I'm not gonna I'm not gonna put point to any of that special, but this one was identifying unknown capability with an unknown explanation and unknown mechanism in a flying animal on this one of particular economic importance on her animal and human health importance and abstract the mechanism by which it's doing that task and then not blindly mimic it. So we didn't create an artificial antenna, but we took the concept and we thought, Well, actually, we could do this more quickly, more simply are more robustly using some off the shelf components which is so abundant they're they're almost free. And then we have ah novel device which can detect obstacles.
[09:54] spk_0: Having collected the data, we were curious to hear more about how the data were analyzed and what they showed.
[10:10] spk_2: The conservative estimate of how high we think that mosquitoes can detect the floor is about 10 or 12 wingspans. So about 20 wing lengths this'd is way in excess of what airline pilots will think of us when ground effect kicks in just before you're about to touch the runway. Ground effect is known to give better lift and drag characteristics on the aircraft, which is very helpful when you're coming into land, but it only really kicks in within one wing span on. So this is way in excess of that 10 times better than that through the jet. So we should be able to do ground following tasks at about that, depending on the type of sensor you're using, because it's a trade off was not a trade off it sort of additive. Really. You have your sensory cue, but you still need a sensor that can detect that information that is available to you. So I mentioned that the mosquitoes have extraordinarily sensitive antennae, which we think allows them to do this wonderful task is great capability they have for us. It's going to depend on the sensors that we attached to any particular aircraft that we put on with the walls because the jet isn't going down. It's slightly less sensitive again. When you purchase one of thes, I'm sure you will. When you try to fly it close to a wall, what you'll notice is that it gets sucked into that wall, and if you fly near the ceiling, it gets sucked into the ceiling as well. So there again, these trade offs with the dynamics of the vehicle that you need to be close enough to detect it but still have a sufficiently agile quadcopter, maybe a racing drone to be ableto get away from it if you realize you're about to crash.
[12:07] spk_1: Research results routinely have both expected and unexpected implications. This lead us to wonder what Richard believes will be the influence of this work. Uh huh.
[12:25] spk_2: On array of applications for this technology, if we're to believe that Amazon will be delivering our parcels in the in the near future, which is, I suppose, particularly relevant in in times such as thes where we're trying to minimize human human contact as much as possible, then we have this utopian or perhaps dystopian, view that the skies will be filled with parcel delivering quad copters. Andi, I don't want those toe fly down, built up areas and crash into a high level of a skyscraper on, then tumbled down onto pedestrians below. So anything which can be used thio reduce the likelihood of crashes. That definitely gets my vote. But this isn't just about parcel delivery. We know that drones are being used for so many different reasons at the moment. Be that search and rescue again in very difficult terrain on indeed unmapped terrain, if it's after a landslide or if it's in a collapsed building. Andi, these air places where you're certainly if you're indoors, it might be that GPS is not something you can use on. In fact, the maps that you had for there may not be relevant anymore anyway. On they might be dark, so you might be flying in situations where using camera based collision avoidance devices, which is what you get on the best commercial quad copters that you could buy. They have cameras around all around them, but there are certain situations in particular when it's dark that they don't work very well. So we're adding a new tool to the suite of collision avoidance devices that could go on toe onto these quad copters on there being used for all that they were being used for agricultural inspection. They're being used as platforms for sporting events on again. If you're moving through wooded areas for that sporting event or something like that, you definitely don't be crashing into the trees or onto the athletes if you're examining civil engineering. So we all know that bridges need to be inspected for cracks, maybe wind turbines in the future. What we need to do is get very, very close to them but not crash into them. Actually, bio inspiration is a really good place to look for this as well. Because not only do we think we've got a technique here where you can get close to but not crash into surfaces. So one of the key benefits of the method that we're proposing in this paper is that it is very lightweight device. Any time you take to the skies, if you add on any device for whatever reason that increases the payload on it reduces the duration for which you can fly or the payload that you can lift other techniques, be they laser range finding or these cameras. They're quite heavy. Also, they take a lot of processing power, so they drain the battery and the lasers emit things. Or the ultra sonics have speakers in which you're admitting these ultrasonic noises at all times, as doesn't require any emission it all other than the down wash, which the vehicle necessarily has to make because it has to obey the laws of physics has to do the equal. And opposite reaction thing has to accelerate air downwards on. So if you could just monitor that with a pressure center, which is virtually passive and requires almost no processing power for the flight controller, then there are significant advantages to be had by that
[15:58] spk_1: that Waas Richard Bum free. Discussing recent research on mosquito inspired biotechnology, you can learn about this research, download a copy of this podcast or read the transcript at science pods dot com.
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