Transcript

Microbots: Medical Infantry | David Cappelleri | TEDxPurdueU

[Music] is a MicroBot microbots what is a micro bot more typically what is a micro robot most people just know it from what they've seen in the movies well the first thing you need to know about a micro robot is it's very small so we say its submillimetre dimensions so for reference a human hair is about 100 microns in diameter so the robots we're talking about here are very small so about 8 human hair is wide but about 7 human hair is tall next thing we need to know about these micro robots as we want them to be mobile to move around in the work space they want to be able to control them wirelessly which is a challenge so if you think about a large-scale robot right you can put a battery in this robot powered up and it goes on its way but what happens if the robot is really small right so you have a tiny little robot you can't stick a battery on this robot it's not going to work so what are we going to do well one thing we can think about doing is maybe we can give this robot a little hat it can make it magnetic and so if we stick a magnet in its workspace it's going to be attracted to that magnet so it's kind of the approach that we take here except we use special mat gets called electromagnets so we can turn these on and off whenever we want to and so we can surround the workspace of the robot with these electromagnets and control it to move in the plane so one of the neat applications for these micro robots is in the body the body has lots of sticky rough surfaces in it so if you wanted to just you know pull our robot with their electromagnet it's going to get stuck in that and that tissue so what can we do well if you think about a car we want to take the car off rodent it's rough terrain we stick big bulky tires on it can negotiate that rough terrain so being fed do the same thing with our robots so now we can give this robot some magnetic feet a little bit mattock different magnetic properties than the ones on its hat and we can add some other electromagnets on the work space and we can turn these on and off now that the robot will now roll and tumble like now and go over this rough terrain just like an all-terrain tire once it gets to our target location and we can then use it to inject some medicine to that target location so that's the idea be assigned this microscope tumbling by a robot that we've developed so it's about three human hairs wide by four human hairs long and it looks like a dumbbell need to bail is a magnetic body buts your oppositely pulled so in one side the North Pole's on the bottom the other side the North Pole's on the top it has two modes of operation so for this tumbling mode what we can do is we can turn your electromagnet on from the bottom and it's going to call the robot to stand up we can turn that field off and put on a somatic field from the side and call the to tilt over then we remove that field it's back on the ground so now we can cycle this you can get the robot to roll and tumble to the target location I also have the second mode of operation which is called a sliding mode operation so in this case once we get to our target location we might have manipulate something there so how this works is we again put a Matic field on the bottom to stand it up then we can tilt it to the side rather than letting it fall back to the ground again we can stand it back up again and we can do this little stick slip motion and then get the robot to kind of walk along the surface and so here's a video of the robots that we fabricated in the lab here at Purdue now so again they're about three human hairs wide by four human hairs long and here we're manually controlling these electrode Mattox turn turning them on and off to get the robot to tumble along the surface so first was on a silicon wafer here we're showing it on some biological tissue so you get a sticky surface what you couldn't just pull this robot across it without having this tumbling locomotion here it's going on top of a penny so now these features of the penny are on the same size of the robot itself it's able to negotiate that surface quite well so then once we get to our target location we want may want to do manipulation there so here's the slotting mode operation so the robot is kind of walking across the surface and here you can see it you know pushing a small little component in this testbed we've also had these robots go over different bumps so here's traversing different bumps on in the work space so it's able to negotiate that quite well we also have these robots going up and down inclined planes so we can go up and down these slopes we're also looking at alternate evacuation techniques it's rather than tumbling the robot end-over-end can we tumble it the other way to get even some even more neat applications and mobility so this is application for these robots is inside the body but there are other biological applications for these robots what you're outside the body and done it in Petri dishes so when biologists use a petri dish the grill typically grow cells and they're all congregated into one area so they would like to take one of these cells move it out from that group perform an experiment on it or they would like to arrange these cells into a certain configuration for the Grillet scalpel there are some other tissue engineering applications so when they do this they typically use a probe and it will move the use of probe and actuate it to push the cell to where it needs to be into it and to arrange it in some certain matter one of the problems with this is that when the user does this they have no idea how much force they're actually pushing the cell with so if you can it they don't know how much force they're applying to the cell you can damage the cell so we'd like to be able to come with the micro robot to help with these kinds of applications also if you look at it at a single cell by itself it's a pretty neat structure it has a nucleus in the middle of the cell and it has a skeleton which is called the cytoskeleton on the inside and so if you push them on this cell with it with a probe and exerts a small force to cell skeleton will actually reconfigure itself to be stiffer where that force was applied and so this is interesting and so the study of these forces and how the cell reacts to it and develops is called mechanobiology is a very popular field and so people interested in trying to study this behavior so again we come with a micro robot can help these applications that would be great finally if you look at two different cells they say L cell a and insell B and you apply the same force to these cells they may deform or deflect in different amounts and this force displacement relationship for the cells is called its stiffness and so if we can have a robot to help us apply these small forces we can record the stiffness of the cells that help to characterize them so a normal cell will have a different stiffness property than say a cancer cell and so which how can we come with the market robot to help with these in vitro or inside a petri dish applications well what we can do is we can add our take our magnetic micro robot so if we have a magnetic body we control the position of it in the petri dish by turning electromagnets on and off but now we need to be able to apply small forces and record those forces so how we're going to do that so we use something called a vision based micro force sensor so what this is it's a soft compliance structure and we know the stiffest of this devices so as it pushes on an object is going to deform we can now observe that deformation with the microscope with a camera attached from a microscope if we know the deformation and we know the stiffness then we can back out what the force is going to be so here's an example some one of these robots called the Micro for sensing mobile micro robot it's about 700 microns footprint so seven human hairs wide seven human hairs long on the back end of it you can see a little magnetic body which we're then using with our electromagnets to control its position orientation in the workspace the end effector that little spring structure is that soft compliant end effector and you see how we're pushing on this microsphere our cell is deforming and we track that and we can then figure out how much force we're using so now we can make sure we play in those cells very safely they also can get this robot to move autonomously so we can plan a path around obstacles in the workspace so it basically gives itself little GPS coordinates then the robot then can follow these GPS coordinates autonomously and then get to the cell and then push it to its target location and this works there's quite well in this case and here we're controlling just one robot at a time so but really cool we control teams and swarms of these robots inside they feature just to have multiple of these robots working independently all at the same time so how can we do that well if we go back to our example with our electromagnets in our in our robots if we have it say a team of three robots and we switch these electromagnets on all these robots are getting the same global fields and so they're all going to do the same thing so the question is how do you get independent control of these robots if they're all magnetic but what these electromagnets are are actually just coils with current running through them so if we can take these coils and we can shrink them down to the same size of the robots roughly and we can kind of turn them on their end right we can then arrange them on the bottom of a petri dish in a big array and then depending on the direction of the current how it flows through these coils we can get an attractive force on the robot or a postive force on the robot and then by planning that and in turn and an attorney these on and off at the right time we can then get independent motion of these teams of microrobots in that network space so we've simulated this this idea and here you can see three robots being controlled by these a planar array of micro coils and we're able to independent control these robots we can also use them for collaborative manipulation so travelling informations to move different objects around in the workspace so we've prototyped a system like this at the millimeter scale well we have these coils which are about four millimeters by four millimeters in size and our robots are two millimeters in diameter and we are actually able to get these robots to move independently in this workspace using this technique so we know this idea is going to work our true goal then is actually to move this not from the millimeter scale and not at the movements but actually use it at the micro scale so how do we do that well it's possible to make these these micro coils or you know along the same size of the robot about 300 microns in diameter it's very hard to do it's very expensive so what can we do that's a little bit cheaper needs and easier to make so if we want to use some standard printed circuit board technology instead of using micro coils we can actually use micro strips of wire and we can arrange them in two layers and it works the same way so now if we have current going in one direction through one of these vertical coils and give us a force to the right on the robot if we change the direction of current then it will give us a force to the left and if we use some of the horizontally mounted coils and micro strips of wire we can now get forces going up and forces going down depending on the direction of the current and so by doing this we can now if we put two micro robots in the workspace we can independently control their positions in the workspace at the same time and someone that need applications here is for advanced manufacturing if you can then use these robots to assemble very small components to commit really interesting devices so we're working on some new 3d printing technology to make essentially micro scale legos and if we can you think of anything if you think of you could make with these legos now you can make here with this system so it's pretty exciting while this is I think a very exciting application I think the more exciting and more impactful applications are the medical domain those are the ones actually hit closer to home for me and I'll tell you why so growing up and part of a big Italian family so this is a picture of me and all my cousins on one side and family is that my grandfather's birthday party a couple years ago we always have a great time we're together and usually the life of the party is my cousin gel which you can see here next to me about four years ago Joe suffered a massive stroke so a stroke is when you have a blood clot moves from somewhere in the body into the brain it cuts off blood flow to the brain if you're lucky you can get a drug and it can dissolve this this this clot or the surging it's in a place in the brain where the surgeon can go when you remove it himself in Joe's case in other people's cases it can be in a deeper part of the brain where it's hard to get out and then the people can suffer with this condition for quite a while and Joe suffered about two years before he passed away with this so this is definitely an unscripted event in Joe's life in my life but I think these events you can also use for inspiration and motivation so now one of my goals is can we design a robot if we can use for the applications like this where the surgeon can't get up the blood clot but the robot can can remove that and help people like Joe to recover learn and return to a healthy life other interesting medical applications that are they're targeted drug delivery so these micro robots remember very small they're run the same size of of cells and also tumors so you can load this with the drugs if you can precisely control where it's going to go you know what's going to get to the tumor site you can actually put a lot more drugs on this and you can how it's efficiently done because those drugs traditionally will get diffused to everywhere in the body so you can have higher concentrations of drugs getting to the target site if you can be delivered with these micro robots hopefully get some better patient outcomes that way another application we break your therapy in this case you have these radioactive seeds which need to be delivered to the tumor site for cancer treatment again you can have Micro robots deliver these to the to the site rather than having a very invasive procedure done which is currently done so hopefully this wouldn't help with recovery don't forget better outcomes as well you also can use these micro robots for biopsies you can add these little spikes or spokes to the end of the robot you can then use them to travel inside the body take a tissue sample bring it and in figure out if it's Kant if a cancerous tumor or not and hopefully again less invasively that it's currently done right now so the bottom line is these micro robots and offer unprecedented capabilities that you just can't get with these larger macro scale robots I mean the future we hope to have these micro robots around the same size of red blood cells with onboard computers cameras intelligence arms hands and all the sorts of interesting things so we could do a lot of different healthcare applications so hopefully have a better idea of what a micro bot is now and you can be excited about these applications as I am in the future if you can think it the microbots can do it [Music] the only limit is your imagination [Music] microbots microbots thank you [Music]