JK Flip Flop II was started in December of 2008, and in May of 2009, had made it past all the rough milestones and was successfully entered into Design Competition 2009!

After 3 seasons, 2 tiebreakers, and 10 rounds, JK Flip Flop II, proud robot of Team Mallet, came away with 1st prize. Among the spoils were $3000, 1 course credit, and 15 minutes of fame.

Our robot navigates using three 100mW lasers. These lasers normally shine on the wall, which is covered with special photoreflective tape. This allows our laser beams to hit the wall, and reflect back exactly to where the laser is, no matter which direction we are facing. This is useful because we can place a phototransistor right next to the laser to pick up the return beam. If a ball is in the way, there will be no return beam, and that is how we can tell if there is a ball there.

After we find the ball, we have a pair of Faulhaber motors with a gearhead attachment that allows us to drive to the ball. We have another motor attached to a bottle brush that sweeps the ball into our hopper. We though the bottle brush was pretty nifty because the flexible brush ends allows us to flex to the contour of the corners of the arena, so we can pick up a ball no matter where it is.

As the ball rolls down the ramp in our hopper, it is stopped by a gate, which is controlled by a servo motor. Servo motors are motors that aren’t too strong or fast, but can turn to an exact angle on command, due to some nifty potentiometer engineering. Also, they sound pretty frikkin sweet, and look real cute (Imagine Wall-E’s arm going up and down, it’s kinda like that…only not as cool).

While in our hopper, the ball is tested for color. We have 3 phototransistors, each with a different color filter, and this can show us the RYB values of the ball. Once we find the color, we aim using an IR phototransistor, and then shoot it with our sweet shooting motor (which was painstakingly crafted by our mechanical engineering teammate for perfect rotation and speed).

Now, biodigesters are an interesting concept. They are essentially giant sealed containers for you to store your poo in. What happens is that the poo is exposed to an oxygen-free environment where anaerobic bacteria thrive. These bacteria are able to consume the organic poo, and in the process, produce biogas. Biogas is very cool because it contains a large volume of methane. Methane is a strong greenhouse gas, it is actually over 20 times worse than carbon dioxide (according to whatever scale they use), and this methane is usually released back into the atmosphere whenever a cow poops or farts. By capturing this biogas, the methane can now be burned as a fuel.

We worked with two partner NGO’s, Green Empowerment and Asofenix. They are both overall pretty frikkin amazing. Asofenix in particular maintains extremely close contact with the families they work with, to the point where they know who in the village is related to who. They also have worked with the families and communities for a long time, not just going in, dabbling, and then bouncing. We saw some signs advertising some other NGO’s scattered around the roads. Funny thing was, no one actually remembers them ever helping out in the communities…

Overall, Nicaragua was pretty darn sweet. Even the Nicaraguan person I sat next to on the flight was awesome. He kept telling me about his experiences on the Chinese cruise ship he worked on. He told me about the places he’s seen, and the Chinese girlfriend that he had. I don’t remember his name, but I remember his face, as well as his girlfriend’s face, since he showed me about a hundred pictures on his phone before it died from low battery. He also told me about his work plan. He usually works 3 to 5 years at a time on the cruise ship, and then returns home to his family for a year with the money he earned. It’s ridiculous to think how globalization can enable a Nicaraguan countryman to travel around the world and see sights many others wouldn’t be able to see, but at the same time, force him away from his home and families for years at a time. He liked his job a lot because he gets to see the world, but he also didn’t sleep for the last three days of travel because he was so excited he finally got to go home again.

At first, we were worried that it would be uncomfortably hot in Nicaragua, since it was so close to the equator, and there wasn’t going to be any fans or AC where we were going to work. However, turns out, the dry season is pretty comfy. The air was dry, and the breezes were refreshing. The sun was hot, but shade was plentiful. The dry season, about December to March, is a great warm place for people afraid of humidity, although you may definitely miss the luscious green that usually pervades Nicaragua.

Once on the ground, he were housed in AsoFenix’s headquarters. I still can’t find their website, but here is Jake from Asofenix’s blog. Anyway, they had a nice little home nestled in a small community a few block away from the airport. First thing I learned there was that people don’t flush toilet paper down the bowl. Instead, they throw it away in the trash. But don’t worry, the toilet paper was so nice smelling that you don’t notice at all.

After a night there, we headed out down the Pan-American Highway to get to el campo, where we were going to be doing our work. Now, if you checked that link, you realize that it is a pretty frikkin long highway. Despite its length, in Nicaragua, it was only two lanes, one going south, one going back north. Another thing we realized while on the highway was that Nicaragua has the coolest public transportation system ever. So remember those giant yellow school buses we rode back in grade school? Well, turns out, when they get too old to pass state inspections, they get driven down to countries like Nicaragua, where they are painted with various hot rod decals and raced around as public transportation buses. I never knew the buses could go so fast, but I quickly learned after the same bus would pass us on the highway, stop for passengers, and then pass us again a few miles down. Also, they are even more badass because they don’t have schedules. They basically run whatever route they usually run, stopping at around the same time, at places like “the corner where Pedro’s Discoteca used to be.”

So later we arrived at the villages we were working with. They were pretty much like the “nong cun” of China. They would farm and live in homes they built themselves, and in both, they would have small TVs with music video disc players. China has their Chinese pop artists, and Nicaragua has their Nicaraguan pop artists. We toured some of the previous projects in the area, and then started work on our own biodigesters.

So my project was to develop and optimize a process for depositing an orderly microsphere monolayer onto photoresist. This is useful because you can then process the photoresist/microsphere combo and create an orderly array of nano-pillars or nano-wells in photoresist. Basically, make shapes out of photoresist that are real small. The process in question was developed previously at our lab, and basically used microspheres to focus UV light subwavelength, which can expose really small areas of photoresist, and ultimately, lead to real small structures. You can read more about it here. Making these small pillars are useful because of their applications in fuel cells, solar cells, and batteries. Normally, these shapes are made with focused ion beams that a machine has to manually punch, which takes forever since each structure is on the order for nanometers, and the goal is cover a large surface area. Plus, it gets pretty expensive since not everyone has a focused ion beam machine.

So my job was to get as many of these microspheres to stick nicely onto the photoresist as possible, which is tricky, because microspheres are hydrophilic and photoresist is hydrophobic. So the first part of my research was to test different surfactants in order to overcome this disagreement. After this problem, the next step was to vary and control different physical properties, such as how fast I was depositing, or what concentration to use. After a nice monolayer was finally formed, the last hurdle was to develop the microspheres and photoresist into nice pillars that were taller than they were wide. After my research, I was able to present at Argonne’s Research Symposium for Undergraduates in Science, which I highly recommend students to apply for, since it is a great opportunity to share your work and hear about what others are up to in your field.

So the competition is usually announced in December, and the actual event is in May. The first few months were pretty crazy though. I actually couldn’t get an LED to light up in a breadboard for like an hour. It sucked. Programming was also a pain. I knew C, but writing C for a PIC was pretty annoying because we didn’t know how to reference pins, or what functions actually worked. Plus, you couldn’t just printf to see what was going on inside the code.

A few months, and several chassis later, our robot began to form. Sometime April, our robot learned to shoot balls, it was pretty sweet. We used a rotating arm with a few magnets attached to the end. The magnets would pick up the ball, and then bring the ball back up to this PVC pipe. The pipe’s entrance had a pretty large lip, so the ball would get caught on the lip, and roll into the pipe. There was a small gate that held the ball in place. Our robot aimed with a little laser on the front, and then would just open the gate to shoot. Go go gadget YouTube video:

We ended up doing alright. We got seeded 4th in the time trials (out of 15). There was a glimmer of false hope when we upset the third best robot in overtime. However, in the next round, our robot failed catastrophically, and for some reason, instead of shooting the ball, just spun in a circle. It was pretty sad, since that round was essentially for third place. Afterward, we received a consolation prize for “Best Ball Shooting.” Overall, it was a good experience, filled with random troubleshooting (once, an IC holder didn’t make proper connections, and I wasted four hours of my life), a solder iron burn (which turned out really nice and silvery), and the feeling that I actually made my first real robot.