Team:Cornell/notebook/drylab/july

Entry:

This afternoon, Dan organized a dry lab meeting focused mostly on the team website. Most of us met our main website designer Eric for the first time today. Tall, skinny and pale, Eric was not timid when it came to voicing his opinions about the website layout. His professionalism and grasp on modern style convinced us that he was the right person to spearhead the construction of our new website.

The subteam discussed the format of the website’s “notebook” section. An ensuing heated debate led us to reevaluate the purpose of the notebook. We drew inspiration primarily from DTU and Imperial College London’s iGEM websites. And we finally agreed that the notebook should be more than a log of activities and should be lean closer toward a blog, conveying information in an engaging, well-organized manner. The notebook would be divided into two general categories: biological and mechanical--each category further dividing into detailed sections (such as naphthalene or chassis design). We decided to emphasize structure with the use of hashtags. Ultimately, entries would start with the date and an interesting one-sentence overview, briefly narrate the day’s events, and end with relevant hashtags.

#website #notebook #hashtag

Entry:

Digging into the details about the chassis, Dan, Manny and I struggled with the roof design. We shied away from a domed roof because of limitations in the machine shop. When we found that that polycarbonate can be bent through heat treatment, so we considered a trapezoidal ceiling that would fit over 3 solar panels. After juggling back and forth between round and edged roof, we went with a triangular roof and a trapezoidal base, creating a septagon (more commonly termed, heptagon) profile. Standing true to our geek roots, we dubbed our prototype “Septimus Prime,” the first remote surveillance vessel equipped to monitor various toxin levels in water for months at a time.

#chassis #optimus prime

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Grabbing our usual tables in the Duffield atrium, we talked about the numbers needed to keep Septimus Prime afloat. In its 120 lb glory, a volume of 0.085m³ is required; however, only the device only holds 0.02m³. We thought it best to deal with the issue by attaching buoys rather than expanding the chassis, which would greatly inhibit portability. Manuel then brought up the figures for the chassis. Weighing around 20 lbs, the chassis should be made lighter. Potential solutions included cutting wedges out of the ¾” aluminum walls and decreasing the number of internal support rods. Ultimately, we opted for another material: polyethylene. Almost as strong as aluminum for about a fifth of its weight and a sixth of its price, polyethylene is a more economical material in every way. Go, plastics!

#chassis #material selection

Entry:

Today, we discussed another problem: sealing. With the current design we had, we needed to completely seal the large opening that is around (or a little below) water level in order to prevent any water from seeping in. We initially planned to put rubber between the top and bottom compartments and screw them together, but we thought that it may make a maintenance more tedious and that it might still be inadequate waterproofing.

Instead, we came up with an idea to move the opening itself higher so that it would be above the water level. We also decided to contact rapid prototyping (i.e., 3D printing) companies to see if we can make the whole chassis in only two solid pieces, a body and a door, instead of having several parts to be constructed. If we do find a company to do this for u, there would be no error from machining to worry about. Sealing problem solved.

#chassis #waterproofing

Entry:

At last, all electronic parts have come in. We have several piezoelectric micropumps made from Germany, an 80 pound car battery as the main power source of the device, and a 24” by 18” solar panel to replenish the battery power. The battery itself is impressive due to its size and weight. Implementing it will be comparable to putting a tank inside our device. On the other hand, the micropumps live up to their namesake; they are barely larger than the size of our thumbs.

After the items were passed around the table, Dan divvied out tasks to dry lab members. Lydia will work on interfacing the microcontroller to the micropumps, while Kelvin and Maneesh are responsible for coding an Android application in which data from the microcontroller can be easily read on a cellphone screen and saved to a server for remote access. And Manny will look into rapid prototyping, a method of fabricating the case for our device.

While we start these tasks, we are also waiting for keycard access into the electrical (ECE) lab.

#chassis #battery #micropump

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Today, we picked up the battery (which was very heavy) and the solar panel before meeting Professor Bruce Land in the ECE lab, which we should have card access to starting this late afternoon. To those who made it on time, Bruce went over general guidelines and safety procedures wearing eye protection when soldering. Unfortunately, Tina arrived too late and missed the training. Only Maneesh, Lydia and Kelvin soldered before, so Bruce demonstrated and reviewed instructions and tips for soldering wires to each other and onto boards. For example, a smooth meniscus between the pin and the board indicates a good connection. Bruce proved very helpful and provided us with prototyping boards, 14-pin sockets and online resources. He later looked over our 80 lb battery, solar panel and micropumps, and suggested that we opt for a smaller, lighter battery for better portability since the solar panel can help compensate for a shorter battery life.

After the professor left for the weekend, we tested our micropumps. When Dan connected the micropump into the microcontroller, which is powered by a computer via USB, the two tiny piezo actuators buzzed to life and everyone let out a sigh of relief. The pumps worked!

In the near future, Maneesh plans to actually test the flow rates in Weill Hall and Lydia will configure the Arduino board (or microcontroller) so that we can get it hooked up to the micropump. On a last note, Bruce Land mentioned that designing our own circuit boards wouldn’t be hard and would look impressive in our final product. He also seems more than willing to share his knowledge and expertise, which we will surely need it as we dive deeper into our system’s electronics.

#electronics #micropump

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After a full team meeting at the spacious Weill Hall, we sat down at the cafe to discuss updates on the chassis so far. For the past few days, Manny had been contacting rapid prototyping companies to get quotes; the ones that got back to him hadn't given a definitive answer because of the lack of a blueprint. The device design that we would send to one such company would be rotationally symmetrical about the vertical axis, with a top hatch that screws into a nearly spherical body. I dubbed it, The Acorn. In the event that we couldn’t afford this option, we needed a secondary design for a device we could produce ourselves. Hence, we returned to the drawing board to design a device better than Septimus Prime, with adequate waterproofing in mind. We debated on designs that involved triple cylindrical vessels, giant buoys and sawed-open propane tanks. It was a mind numbing, paper scratching, and at times, nearly frustrating process. But refocusing on an apparatus with one body and a top opening, in the end, we went with the next best thing: Septimus Prime with a top latch opening, much like a submarine.

#chassis #acorn

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The selection process was unrelenting yet again. Despite moving the opening to above water level, waterproofing would still be a nightmare. What we really needed was a single-piece, solid molded chassis, so we searched online for all kinds of diecast--aluminum, ABS, polycarbonate, etc. However, all materials had their issues, such as size and cost. Along the way though, we came across Pelican cases. After some quick calculations, we found cases that float well and worth the price. Dan also praised them for their badass looks. From the wide online selection, we decided to go with the Pelican 1650. Next time, we need to discuss the modifications that need to be made to the case.

On the electronics side of the story, Arduino requires a “programmer device” to load the code onto the microcontroller, so we need to get one from Bruce. In the meantime, Lydia was able to get simulations running on her laptop. And as always, Kelvin continued typing away on his disintegrating laptop, programming the server.

#chassis #electronics #Arduino

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First off, we established that the solar panel should be housed in a polycarbonate prism, external to the Pelican case. We then went on to discuss how many holes we would drill into the Pelican case, which led back to the much debated topic of waterproofing. We decided we would drill one hole and fix a short, large tube through it with epoxy or another sealant. The input, output and effluent water channels and solar panel wires would run through this large tube; any remaining space in the tube would also be sealed. Dan brought up the issue of separating the three water channels so that wastewater does not get pumped back into system. To solve this problem, we looked online for some rigid plastic tube separators.

Now that most aspects have been considered, the design is as close to complete as it will ever be. It has been a long process, and we are glad to be moving on to the next step. Dan will order the Pelican case soon and we are all looking forward to the manufacture stage.

#chassis #waterproofing

Entry:

Yesterday, we picked up the Pelican 1650 at the shipping storage room. When we took it out of the box, its large, black, chiseled surfaces and side locks made it look more intimidating face to face. A very observant Manny pointed out the lifetime guarantee on the box, which stated the case is built to withstand everything except for shark bites, bear attacks, and children under 5. We had a few good laughs there before we looked through the rest of our inventory: the polycarbonate tube and DelRen rod that were initially planned to make the bioreactor shell; the graphite rods, luer fittings from Cole-Palmer, and a free sample of septas from Restek for the bioreactor; and the valves and tubes for the micropumps.

We were also going to start machining yesterday. However, when we arrived at the Emerson machine shop, we found out that it was closed until August 6th for maintenance, which drastically pushes back our schedule for production. Chie and Tina left, while the rest of us went to try the machine shop at Clark Hall. To work there, we need to take a 24 hour training course in order to use those machines, so we decided to pay the shop to machine the bioreactor. That way, Dylan can start running tests in the new bioreactor as soon as possible. We will machine another three bioreactors ourselves once the Emerson shop reopens.

#chassis #bioreactor