Sunday, May 20, 2012

Tech Dinghy Challenge!

Hey guys!

Last friday was the very first annual Tech Dinghy Challenge at the MIT Sailing Pavilion!

Next House (my old dorm) put together a team for this event full of craziness, sailing and burgers (how could I miss it!?) The competition consisted of getting a team of people and then everyone had to eat at least one burger in 5 minutes time then we had to cram as many people in a boat as possible (modifications were allowed) and then sail to the boston shore and come back! Points were awarded for burgers eaten, people in boat and crossing time.

We modified the tech (sailboat) by adding outriggers with inflatables. We built it desperately in the hours before the competition and honestly I was not sure if it was going to work but PROPS to the designers, they did an awesome job and our modifications were rock solid! Here is a pic of us before putting the boat in the water...

I was fortunate enough to skipper the boat. With so many people on board I had to make use of every resource possible to steer the boat (rudder, sail... even paddles!). IT WAS AWESOME! We had so many sailboats around us taking pictures and throwing water at us! Some incompetent boats even crashed into us which made me extremely mad (why on earth would you crash into a boat with 30 people that is almost sinking?) at some point I was about to jump into the water swim into their boat and pull their rudder out for vengeance. However I desisted...

But my FAVORITE PART was the grand finale, and as videos speak louder than words...

Awesome right? Props to Jeff from the dockstaff who sank us with the wake of his boat! We eventually had to bail the boat to prevent it from sinking into the charles for ever ajajajajja!

I can't wait for next year's challenge! Big shout out to the next house team!


Tuesday, May 15, 2012

Flavorful Borderline Racist Video

So... I'm taking an awesome class called 4.301 - Intro to Visual Arts. And for our first assignment in this class we did a video project. At the start I was not sure of what I wanted to do with my video but with help from my friends and some random inspiration that happens very late at night I decided to do something ridiculous (surprise surprise!)

The video is pretty self explanatory:

So... yeah not self explanatory at all ajaj! The assignment for this video was to think of the theme "Shaping Time" and alto to think about "circuits and systems". I decided to change the name to "Shopping Time" and then to use the supermarket at the system to study, i found the supermarket an interesting system because so many different cultures combine in a small very efficient space. I dressed up with a huge clock to relate to the "shaping time" theme (contrary to public opinion I did not want to emulate flavor flav, actually i did not know who he was when i decided on my outfit). The music was one of my favorite parts because it allowed me to present the different cultures and circumstances via audio and sound.

My prof. really liked the video and even called it "borderline racist", which I am not sure if it is a compliment or not.

Monday, May 14, 2012

Hematocrit Centrifuge


I am sure many of you guys have heard of D-Lab... but just in case I'll explain: D-Lab is a group at MIT that designs solutions to problems in the third world, they try to alleviate poverty and improve people's quality of life thought Design, Dialogue and Dissemination (thus the D in D-Lab).

I took D-Lab Design this semester and out team designed a Hematocrit Centrifuge! A H. Centrifuge is a key tool in diagnosing anemia, you basically spin blood for 5 min and then look at the proportion of red to clear solution (red blood cells to plasma) and from this you can diagnose anemia (a normal human has 40-45% red stuff). Given that most people with anemia live in the developing world, they need rapid ways to diagnose it however industry grade centrifuges cost more than a $1000 and require electricity which is a no-no for a lot of rural clinics out there.

Thus our team designed a centrifuge that could be built for around $40-100 using a power drill transmission. We took apart a drill and used the gear box to provide a good gear reduction for the spinning of blood. Here is a picture of the final design:

Our design has a footprint of about 1' by 1' by < 2', which is a big reduction from our Nigerian Community partner's bike centrifuge. My favorite feature of the centrifuge is that we put in a loose nut in the handle that rattles around when it goes too slow but when the speed is fast enough the centrifugal acceleration overcomes gravity and the nut sticks to the outside. This is how we make sure we are spinning the blood fast enough. Here is some of the math:

wooo! 2.003 in action!

I had my blood drawn at a clinic and then we spun the blood and got pretty good results! We even spun some diluted blood (to simulate anemic conditions):

woooo! I am not anemic!

My group is continuing our communications with Dr. Awojobi (an awesome doctor/designer in Nigeria) to flesh out details on a new design of a centrifuge based on a hand drill. So far he has sent us this picture of his progress so far:

exciting prototype!

Hopefully he can implement this new design successfully in Nigeria and disseminate it around the world! Meanwhile I will try and see if people back home in El Salvador have an interest in the hand crank centrifuge we built! I'll keep you guys posted! Here is a video of us testing out the centrifuge (a big shout out to my awesome teammates (Melvin Salinas, Kwami "The King" Williams, Daisy Chang and Kevin Kung)

(a shout out for my other roomie and lil bro David who I just learned also has a blog!)

UPDATE: 16 May 2012

Dr Awojobi (our partner from Nigeria) just emailed us saying that he has successfully implemented hand drills into his prototype and came up with a model that is about a third of the size of the prototype he has been using for 11 years and costs half as much! Here is a pic:

It is really exciting to see that what we worked on during the semester has had real impact on a someones life!

Stepper Scanner Control

If you know me at MIT, your probably know that I really enjoy controls and mechatronics. Even though my degree says "Mechanical and Ocean Engineering" I have done most of not all my requirements studying control theory and practical applications of control.

This blog post is about the controller design for a lithographic stepper. A "stepper" is a essentially a read head that moves in steps on a silicon wafer while the wafer is exposed to UV radiation. The catch is that the error in position during the half second of UV curing is on the order of tens of nanometers. For my digital controls class, we had to come up with a design for the controller structure.

Although we did not have the opportunity to implement the controller in real hardware, our professor included a lot of non-linearities and real world problems and parameters (he even brought in an old stepper to class) which made the problem incredibly interesting.

Here is a picture of the model for the stepper.

yep... its pretty convoluted! but luckily the professor helped us derive the state space model in class and thus we could focus on the control design of the stage.

We used completely classical control techniques (screw LQR and Kalman filters!) including decoupling and trajectory generations to get optimal performance. Most of the analysis was done is simulink, here is a screenshot of the final simulink model!

The final controller took over 36hrs of work to figure out but it worked great (in theory!) and I learned a great ton about design in controllers and how to be able to compensate for disturbances, noise, saturations and more of those great things that pop up in the real world. 

This was an awesome project to do and hopefully a good intro to my maybe job this summer at ASML!

Thanks to Prof. Trumper and all my controlfreak buddies for the collaboration during 2.171!

Re-Induction of Blog Motion!

Hey guys!
  I have recently (yesterday) decided to restart this blog!

 After being inspired by my awesome roomie Vicky Rodriguez I have decided to revamp my blog and make it a maker blog!

 I'll be posting about stuff I have made/taken apart for classes, for fun, or just random ideas that I have! Please feel free to submit any ideas or comments and I'll definitely take into account your feedback!

For this re-induction post I have decided to talk about a simple Induction Motor me and my roommates made at 2am in September 2011 because we were bored.

Here is a video of the motor running!

 I have recently been really interested in induction motors, ever since I found out about them I cant stop thinking of possibilites to use them (of course, them being such an "old" technology most of their uses have been figured out).

 A induction motor works on the principle of electromagnetic induction (surprise, surprise!), AC is pumped into the stator coils which induces a current in the rotor (a lid in my motor) and this induced current tries to catch up to the changing magnetic field in the stators. Thus we get motion without no mechanical connection whatsoever!

 The motor is classified as a split phase motor, this is because I used one voltage source (a 9V RMS 60Hz sinusoid) and then hooked up one stator coil in series with 220uF a capacitor to create a phase shift which gives the motor self starting capabilities.

 Credits to Nikola Tesla, the real life Tony Stark who invented the induction motor (as well as a myriad of other devices!)

 Thanks for reading guys and please stay tuned to the blog! I'll to try update the website very regularly and document what I do!