Team:Cornell/notebook/drylab/june
From 2012.igem.org
(Difference between revisions)
(7 intermediate revisions not shown) | |||
Line 61: | Line 61: | ||
Welcome to the Dry Lab Blog! We start off with fresh ideas for the biosensor. | Welcome to the Dry Lab Blog! We start off with fresh ideas for the biosensor. | ||
- | <a href="#" class="technical-desc" for="#technical- | + | <a href="#" class="technical-desc" for="#technical-desc1" style="display:block;margin-top:20px;">Details</a> |
- | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical- | + | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical-desc1"> |
<h6>Entry:</h6> | <h6>Entry:</h6> | ||
Dry Lab met up for the first time to brainstorm designs for a biosensor that would allow a steady flow of water in and out, sustain genetically modified bacteria, process electrical signals coming from the culture, and communicate that information to a remote device. Before we began, however, we all introduced ourselves: Dan, Dylan, Maneesh, Tina, Lydia, Caleb, Chie and me (Robert). After a brief casual exchange, we quietly thought about functional requirements for the system before sharing them around the table. These requirements helped us brainstorm and refine our designs. Dan the Dry Lab leader then split us into groups to form ideas about various components, such as the pump mechanism, food delivery, water filtration and power source. We sketched and made bullet point descriptions, and aimed for 3 distinct designs. Knowing the functional requirements organized our thoughts and later refine our designs after the critique session. We passed our transcribed ideas around and commented on other people’s papers with post-its. With the new feedback, we returned to the drawing board to improve our concepts in the remaining time. Before the meeting was adjourned, we were assigned to research products or methods related to our components.<p></p> | Dry Lab met up for the first time to brainstorm designs for a biosensor that would allow a steady flow of water in and out, sustain genetically modified bacteria, process electrical signals coming from the culture, and communicate that information to a remote device. Before we began, however, we all introduced ourselves: Dan, Dylan, Maneesh, Tina, Lydia, Caleb, Chie and me (Robert). After a brief casual exchange, we quietly thought about functional requirements for the system before sharing them around the table. These requirements helped us brainstorm and refine our designs. Dan the Dry Lab leader then split us into groups to form ideas about various components, such as the pump mechanism, food delivery, water filtration and power source. We sketched and made bullet point descriptions, and aimed for 3 distinct designs. Knowing the functional requirements organized our thoughts and later refine our designs after the critique session. We passed our transcribed ideas around and commented on other people’s papers with post-its. With the new feedback, we returned to the drawing board to improve our concepts in the remaining time. Before the meeting was adjourned, we were assigned to research products or methods related to our components.<p></p> | ||
Line 70: | Line 70: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src="https://static.igem.org/mediawiki/2012/a/aa/Dry_Lab_June_6_Notebook.JPG"> |
</div> | </div> | ||
</div> | </div> | ||
Line 80: | Line 80: | ||
<p></p> | <p></p> | ||
- | Dry Lab takes a close look at batteries and discusses various approaches to food delivery. <a href="#" class="technical-desc" for="#technical- | + | Dry Lab takes a close look at batteries and discusses various approaches to food delivery. <a href="#" class="technical-desc" for="#technical-desc2" style="display:block;margin-top:20px;">Details</a> |
- | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical- | + | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical-desc2"> |
<h6>Entry:</h6> | <h6>Entry:</h6> | ||
This past week, I learned that summer in Ithaca is much quieter than during the fall and spring semesters, but has much nicer weather and beautiful scenery. On the other side of the window, the second Dry Lab meeting was in session. Manny and Kelvin had come on board the Dry Lab team recently. Introductions aside, all of us took turns presenting our findings on pumps, filters, batteries and other components that would go into our biosensor system.<p></p> | This past week, I learned that summer in Ithaca is much quieter than during the fall and spring semesters, but has much nicer weather and beautiful scenery. On the other side of the window, the second Dry Lab meeting was in session. Manny and Kelvin had come on board the Dry Lab team recently. Introductions aside, all of us took turns presenting our findings on pumps, filters, batteries and other components that would go into our biosensor system.<p></p> | ||
Line 91: | Line 91: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/9/98/Discussion_with_Dan.JPG "> |
</div> | </div> | ||
</div> | </div> | ||
Line 113: | Line 113: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src="https://static.igem.org/mediawiki/2012/f/f0/Water_Flow.JPG"> |
</div> | </div> | ||
</div> | </div> | ||
Line 123: | Line 123: | ||
<p></p> | <p></p> | ||
- | Decisions have been made! With flow method and battery selected, we move onto pumps. <a href="#" class="technical-desc" for="#technical- | + | Decisions have been made! With flow method and battery selected, we move onto pumps. <a href="#" class="technical-desc" for="#technical-desc4" style="display:block;margin-top:20px;">Details</a> |
- | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical- | + | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical-desc4"> |
<h6>Entry:</h6> | <h6>Entry:</h6> | ||
Maneesh and Dylan made a presentation for discrete flow. The system seems to be complicated, as it involves pressure gradients and the use of feedback loops and modifiers to generate pressure equalization. Since simplicity is a top priority, we returned to continuous flow because it would be easier to implement and still fulfill the functional requirements. <p></p> | Maneesh and Dylan made a presentation for discrete flow. The system seems to be complicated, as it involves pressure gradients and the use of feedback loops and modifiers to generate pressure equalization. Since simplicity is a top priority, we returned to continuous flow because it would be easier to implement and still fulfill the functional requirements. <p></p> | ||
Line 144: | Line 144: | ||
Honey, I shrunk the pump! Team is baffled by the micropump. | Honey, I shrunk the pump! Team is baffled by the micropump. | ||
- | <a href="#" class="technical-desc" for="#technical- | + | <a href="#" class="technical-desc" for="#technical-desc5" style="display:block;margin-top:20px;">Details</a> |
- | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical- | + | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical-desc5"> |
<h6>Entry:</h6> | <h6>Entry:</h6> | ||
We scrapped the marine bilge pump because we found micropumps! They are so small and light that theoretically (and don’t quote me on this) you could swallow it and find it intact 3-5 days later in the bathroom. Most importantly, they fit the flow rate requirement and are low power. Chie calculated that the system with the micropump can run for a month exclusively off of the battery. Of course, this was very exciting news for the team! Afterward, we performed analysis on the battery dimensions--specifically weight and volume. We needed the numbers to fit the constraints of preliminary chassis designs.<p></p> | We scrapped the marine bilge pump because we found micropumps! They are so small and light that theoretically (and don’t quote me on this) you could swallow it and find it intact 3-5 days later in the bathroom. Most importantly, they fit the flow rate requirement and are low power. Chie calculated that the system with the micropump can run for a month exclusively off of the battery. Of course, this was very exciting news for the team! Afterward, we performed analysis on the battery dimensions--specifically weight and volume. We needed the numbers to fit the constraints of preliminary chassis designs.<p></p> | ||
Line 164: | Line 164: | ||
For realization of the biosensor, the Geek Squad discusses electrical components. | For realization of the biosensor, the Geek Squad discusses electrical components. | ||
- | <a href="#" class="technical-desc" for="#technical- | + | <a href="#" class="technical-desc" for="#technical-desc6" style="display:block;margin-top:20px;">Details</a> |
- | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical- | + | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical-desc6"> |
<h6>Entry:</h6> | <h6>Entry:</h6> | ||
Wednesday is now designated meeting time for the electronic aspect of the system. At the start, Dan made a chart of broad objectives that were broken down into tasks. Objectives include circuitry build, implementation of microcontroller and data transmission. An electrical engineering major, Lydia was the most knowledgeable one as we looked for analog-to-digital converters (ADC) and microcontrollers. <p></p> | Wednesday is now designated meeting time for the electronic aspect of the system. At the start, Dan made a chart of broad objectives that were broken down into tasks. Objectives include circuitry build, implementation of microcontroller and data transmission. An electrical engineering major, Lydia was the most knowledgeable one as we looked for analog-to-digital converters (ADC) and microcontrollers. <p></p> | ||
Line 184: | Line 184: | ||
Mm mm... talk about food and open grills. | Mm mm... talk about food and open grills. | ||
- | <a href="#" class="technical-desc" for="#technical- | + | <a href="#" class="technical-desc" for="#technical-desc7" style="display:block;margin-top:20px;">Details</a> |
- | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical- | + | <div class="hide-me panel" style="background:white;margin-top: 20px;" id="technical-desc7"> |
<h6>Entry:</h6> | <h6>Entry:</h6> | ||
Yesterday, the microcontroller for our entire system, the Arduino ADK, was the first item to arrive! Produced in Italy, it seems like a neat, little thing. While we glossed over the board, Lydia and Kelvin went over some details regarding data transfer from the board to an Android phone. After settling down, our first line of business was to finalize the method for storing the viscous yeast-rich food source. Although we initially planned to machine a PVC cylinder, the issue of pressure building up due to airtightness led us to consider IV drip bags instead. Simple enough, the transparent pouches would deflate as food was depleted and give a clear indication of how much food is left.<p></p> | Yesterday, the microcontroller for our entire system, the Arduino ADK, was the first item to arrive! Produced in Italy, it seems like a neat, little thing. While we glossed over the board, Lydia and Kelvin went over some details regarding data transfer from the board to an Android phone. After settling down, our first line of business was to finalize the method for storing the viscous yeast-rich food source. Although we initially planned to machine a PVC cylinder, the issue of pressure building up due to airtightness led us to consider IV drip bags instead. Simple enough, the transparent pouches would deflate as food was depleted and give a clear indication of how much food is left.<p></p> | ||
Line 221: | Line 221: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src="https://static.igem.org/mediawiki/2012/a/aa/Dry_Lab_June_6_Notebook.JPG"> |
</div> | </div> | ||
</div> | </div> | ||
Line 237: | Line 237: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/9/98/Discussion_with_Dan.JPG "> |
</div> | </div> | ||
</div> | </div> | ||
Line 252: | Line 252: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src="https://static.igem.org/mediawiki/2012/f/f0/Water_Flow.JPG"> |
</div> | </div> | ||
</div> | </div> | ||
Line 279: | Line 279: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/c/c4/06_23.jpg "> |
</div> | </div> | ||
</div> | </div> | ||
Line 292: | Line 292: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/8/82/06_27.jpg "> |
</div> | </div> | ||
</div> | </div> | ||
Line 306: | Line 306: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/2/25/06_30.jpg "> |
</div> | </div> | ||
</div> | </div> | ||
Line 338: | Line 338: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src="https://static.igem.org/mediawiki/2012/a/aa/Dry_Lab_June_6_Notebook.JPG"> |
</div> | </div> | ||
</div> | </div> | ||
Line 362: | Line 362: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/9/98/Discussion_with_Dan.JPG "> |
</div> | </div> | ||
</div> | </div> | ||
Line 383: | Line 383: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src="https://static.igem.org/mediawiki/2012/f/f0/Water_Flow.JPG"> |
</div> | </div> | ||
</div> | </div> | ||
Line 418: | Line 418: | ||
We scrapped the marine bilge pump because we found micropumps! They are so small and light that theoretically (and don’t quote me on this) you could swallow it and find it intact 3-5 days later in the bathroom. Most importantly, they fit the flow rate requirement and are low power. Chie calculated that the system with the micropump can run for a month exclusively off of the battery. Of course, this was very exciting news for the team! Afterward, we performed analysis on the battery dimensions--specifically weight and volume. We needed the numbers to fit the constraints of preliminary chassis designs.<p></p> | We scrapped the marine bilge pump because we found micropumps! They are so small and light that theoretically (and don’t quote me on this) you could swallow it and find it intact 3-5 days later in the bathroom. Most importantly, they fit the flow rate requirement and are low power. Chie calculated that the system with the micropump can run for a month exclusively off of the battery. Of course, this was very exciting news for the team! Afterward, we performed analysis on the battery dimensions--specifically weight and volume. We needed the numbers to fit the constraints of preliminary chassis designs.<p></p> | ||
On a last note, here is a brief recapitulation. The general layout of operations has been established: a micropump will provide continuous fluid flow through the bioreactor; a compression device will introduce the liquid-based food source into the flow upstream of the bioreactor. Ultimately, the objective is to make a steady state biosensor that can run autonomously for 6 months.<p></p> | On a last note, here is a brief recapitulation. The general layout of operations has been established: a micropump will provide continuous fluid flow through the bioreactor; a compression device will introduce the liquid-based food source into the flow upstream of the bioreactor. Ultimately, the objective is to make a steady state biosensor that can run autonomously for 6 months.<p></p> | ||
+ | |||
#micropump #battery #recap | #micropump #battery #recap | ||
Line 423: | Line 424: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/c/c4/06_23.jpg "> |
</div> | </div> | ||
</div> | </div> | ||
Line 442: | Line 443: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/8/82/06_27.jpg "> |
</div> | </div> | ||
</div> | </div> | ||
Line 462: | Line 463: | ||
</div> | </div> | ||
<div class="three columns"> | <div class="three columns"> | ||
- | <img src="https://static.igem.org/mediawiki/2012/ | + | <img src=" https://static.igem.org/mediawiki/2012/2/25/06_30.jpg "> |
</div> | </div> | ||
</div> | </div> |
Latest revision as of 03:34, 27 October 2012
Dry Lab - June
-
June 6th
Focus: General Brainstorming
Welcome to the Dry Lab Blog! We start off with fresh ideas for the biosensor. DetailsJune 9th
Focus: Biosensor Components Dry Lab takes a close look at batteries and discusses various approaches to food delivery. DetailsJune 13th
Focus: System Flow Discrete versus continuous: debate on food and water delivery system continues. DetailsJune 16th
Focus: System Flow Decisions have been made! With flow method and battery selected, we move onto pumps. DetailsJune 23th
Focus: Water Pump Honey, I shrunk the pump! Team is baffled by the micropump. DetailsJune 27th
Focus: Electronics For realization of the biosensor, the Geek Squad discusses electrical components. DetailsJune 30th
Focus: Food Containment; Design of Chassis Mm mm... talk about food and open grills. Details -
June 6th
Dry Lab met up for the first time to brainstorm designs for a biosensor that would allow a steady flow of water in and out, sustain genetically modified bacteria, process electrical signals coming from the culture, and communicate that information to a remote device. Before we began, however, we all introduced ourselves: Dan, Dylan, Maneesh, Tina, Lydia, Caleb, Chie and me (Robert). After a brief casual exchange, we quietly thought about functional requirements for the system before sharing them around the table. These requirements helped us brainstorm and refine our designs. Dan the Dry Lab leader then split us into groups to form ideas about various components, such as the pump mechanism, food delivery, water filtration and power source. We sketched and made bullet point descriptions, and aimed for 3 distinct designs. Knowing the functional requirements organized our thoughts and later refine our designs after the critique session. We passed our transcribed ideas around and commented on other people’s papers with post-its. With the new feedback, we returned to the drawing board to improve our concepts in the remaining time. Before the meeting was adjourned, we were assigned to research products or methods related to our components. #hello #brainstormingJune 9th
This past week, I learned that summer in Ithaca is much quieter than during the fall and spring semesters, but has much nicer weather and beautiful scenery. On the other side of the window, the second Dry Lab meeting was in session. Manny and Kelvin had come on board the Dry Lab team recently. Introductions aside, all of us took turns presenting our findings on pumps, filters, batteries and other components that would go into our biosensor system. For the power source, there were 3 different types of batteries to consider: lithium, lead acid and silver ion. Tina informed that silver ion would be most expensive as it was still relatively new technology. However, it was the most energy dense source. Between lithium and lead acid, lithium has a greater power-to-weight ratio but lost its capacity to hold charge even when not in use, while the lead acid was clunkier (heavier and larger) and better equipped to deliver large jolts of power. For food delivery and water filtration methods, we began a discussion about a combination of pump and gravity-fed designs to save power and extend battery life. Related to that matter, we talked about discrete versus continuous flow of food and water into the bacterial culture but were cut short on time. At home, we continued research on our assigned components, looking mostly at product price, functionality and performance. #power #battery #filtrationJune 13th
Today was a huge discussion day, in which we continued our previous discussion on fluid flow through the system. Last time, we leaned toward a discrete system because it would cut energy costs due to less activity. However, Dylan told us today that discrete flow would not work because the culture needs to maintain steady state. According to the equations and graphs he drew on the whiteboard, discrete flow would not satisfy this requirement. Any deviation from steady state would add noise to the electrical output from bacteria, rendering the biosensor inaccurate. Still, Maneesh and Dylan tried to design a discrete system that would work. A programmable fish food dispenser would periodically release food into the bioreactor that held the bacterial culture. And a microcontroller would be used to activate the water pump. However, the issue of maintaining steady state still lingered. On the whiteboard, we also came up with two other designs--a passive gravity fed system and a continuous model. For continuous flow, pumps would be constantly churning food and water into the bioreactor. The disadvantages are incredibly low flow rates (meaning higher-end machines) and greatest power consumption. In the passive system, food and water input from above the water level would flow down into the bioreactor. This design allowed for continuous flow and least energy consumption. However, the bulk of this system would need to be strictly underwater, so we would have to look into waterproofing. #filtration #flow #gravityJune 16th
Maneesh and Dylan made a presentation for discrete flow. The system seems to be complicated, as it involves pressure gradients and the use of feedback loops and modifiers to generate pressure equalization. Since simplicity is a top priority, we returned to continuous flow because it would be easier to implement and still fulfill the functional requirements. During further discussion, we did a back-of-the-envelope calculation for a continuous flow rate of water. It came out to be 0.03 milliliters per minute, which meant we needed a very precise, slow-acting pump. For the purpose of conserving energy, Dan found some low power pumps, including a $5 Chinese manufactured pump and a $20 500 GPH (gallons per hour) bilge pump. However, more research is required to find the optimal pump. We also thought about methods for introducing food into the stream. One idea was to use a worm-gear compressor to slowly push through our system. Chie presented candidates for our biosensor battery. We selected a 100Ah deep cycle gel cell battery, after listening to suggestions from several professors. Lydia and others discussed meeting with ECE professors to figure out the logistics of the circuitry component. We have a rough plan for developing the potentiostat, which is vital for measuring changes in potential, or signal produced by the bacteria when they detect toxins in the water. #flow #pump #battery #potentiostatJune 23th
We scrapped the marine bilge pump because we found micropumps! They are so small and light that theoretically (and don’t quote me on this) you could swallow it and find it intact 3-5 days later in the bathroom. Most importantly, they fit the flow rate requirement and are low power. Chie calculated that the system with the micropump can run for a month exclusively off of the battery. Of course, this was very exciting news for the team! Afterward, we performed analysis on the battery dimensions--specifically weight and volume. We needed the numbers to fit the constraints of preliminary chassis designs. On a last note, here is a brief recapitulation. The general layout of operations has been established: a micropump will provide continuous fluid flow through the bioreactor; a compression device will introduce the liquid-based food source into the flow upstream of the bioreactor. Ultimately, the objective is to make a steady state biosensor that can run autonomously for 6 months. #micropump #battery #recapJune 27th
Wednesday is now designated meeting time for the electronic aspect of the system. At the start, Dan made a chart of broad objectives that were broken down into tasks. Objectives include circuitry build, implementation of microcontroller and data transmission. An electrical engineering major, Lydia was the most knowledgeable one as we looked for analog-to-digital converters (ADC) and microcontrollers. In order to send data wirelessly, we decided to go with transmission over a cell phone network. First, the electrical signal from the bioreactor would be sent to the microcontroller; the microcontroller would be connected to a cellphone, which would then broadcast the data to a remote location. Kelvin as the computer science guy was the prime candidate for developing an Android application that would act as the interface between the microcontroller and phone. #potentiostat #electronics #microcontroller #ADC #Android #phoneJune 30th
Yesterday, the microcontroller for our entire system, the Arduino ADK, was the first item to arrive! Produced in Italy, it seems like a neat, little thing. While we glossed over the board, Lydia and Kelvin went over some details regarding data transfer from the board to an Android phone. After settling down, our first line of business was to finalize the method for storing the viscous yeast-rich food source. Although we initially planned to machine a PVC cylinder, the issue of pressure building up due to airtightness led us to consider IV drip bags instead. Simple enough, the transparent pouches would deflate as food was depleted and give a clear indication of how much food is left. On a different note, these last few days have been inundated with ideas for housing the equipment. The chassis is required to float on the water surface and withstand the impact of a log traveling downstream. We also voted to place the solar panels within the case, spurring the need for a transparent rooftop; desiccant would prevent the inside from fogging up. Several messy sketches later, we envisioned a cylindrical chassis: a semi-cylindrical ceiling that mirrors the base. The roof would be some type of polycarbonate bent into a semicircle fixed on either side by the thin aluminum or steel walls that would provide strength for the casing. Steel rods would . After accounting for weight, we thought it best to similarly incorporate the cheaper and lighter polycarbonate material into the base. Our design resembles a grill, with the top half opening up like a briefcase. The solar panels are fixed to the roof. There are two mid-level trays to attach the Arduino board, bioreactor, food and micropumps, and one lower tray for the battery. To prevent contamination and promote portability, everything except the battery is installed into the chassis before deployment. The reactor is fixed to a swiveling plate on the tray to minimize sloshing and disturbance when someone is carrying the case. Once at the site, a person would need to only do 3 things: place the battery into the case, move the case out into the water and secure it to an anchor. Ultimately, our tentative design is streamlined for simplicity and portability. #food #chassis #grill #deployment -
June 6th
Focus: General Brainstorming Welcome to the Dry Lab Blog! We start off with fresh ideas for the biosensor.Entry:
Dry Lab met up for the first time to brainstorm designs for a biosensor that would allow a steady flow of water in and out, sustain genetically modified bacteria, process electrical signals coming from the culture, and communicate that information to a remote device. Before we began, however, we all introduced ourselves: Dan, Dylan, Maneesh, Tina, Lydia, Caleb, Chie and me (Robert). After a brief casual exchange, we quietly thought about functional requirements for the system before sharing them around the table. These requirements helped us brainstorm and refine our designs. Dan the Dry Lab leader then split us into groups to form ideas about various components, such as the pump mechanism, food delivery, water filtration and power source. We sketched and made bullet point descriptions, and aimed for 3 distinct designs. Knowing the functional requirements organized our thoughts and later refine our designs after the critique session. We passed our transcribed ideas around and commented on other people’s papers with post-its. With the new feedback, we returned to the drawing board to improve our concepts in the remaining time. Before the meeting was adjourned, we were assigned to research products or methods related to our components. #hello #brainstormingJune 9th
Focus: Biosensor Components Dry Lab takes a close look at batteries and discusses various approaches to food delivery.Entry:
This past week, I learned that summer in Ithaca is much quieter than during the fall and spring semesters, but has much nicer weather and beautiful scenery. On the other side of the window, the second Dry Lab meeting was in session. Manny and Kelvin had come on board the Dry Lab team recently. Introductions aside, all of us took turns presenting our findings on pumps, filters, batteries and other components that would go into our biosensor system. For the power source, there were 3 different types of batteries to consider: lithium, lead acid and silver ion. Tina informed that silver ion would be most expensive as it was still relatively new technology. However, it was the most energy dense source. Between lithium and lead acid, lithium has a greater power-to-weight ratio but lost its capacity to hold charge even when not in use, while the lead acid was clunkier (heavier and larger) and better equipped to deliver large jolts of power. For food delivery and water filtration methods, we began a discussion about a combination of pump and gravity-fed designs to save power and extend battery life. Related to that matter, we talked about discrete versus continuous flow of food and water into the bacterial culture but were cut short on time. At home, we continued research on our assigned components, looking mostly at product price, functionality and performance. #power #battery #filtrationJune 13th
Focus: System Flow Discrete versus continuous: debate on food and water delivery system continues.Entry:
Today was a huge discussion day, in which we continued our previous discussion on fluid flow through the system. Last time, we leaned toward a discrete system because it would cut energy costs due to less activity. However, Dylan told us today that discrete flow would not work because the culture needs to maintain steady state. According to the equations and graphs he drew on the whiteboard, discrete flow would not satisfy this requirement. Any deviation from steady state would add noise to the electrical output from bacteria, rendering the biosensor inaccurate. Still, Maneesh and Dylan tried to design a discrete system that would work. A programmable fish food dispenser would periodically release food into the bioreactor that held the bacterial culture. And a microcontroller would be used to activate the water pump. However, the issue of maintaining steady state still lingered. On the whiteboard, we also came up with two other designs--a passive gravity fed system and a continuous model. For continuous flow, pumps would be constantly churning food and water into the bioreactor. The disadvantages are incredibly low flow rates (meaning higher-end machines) and greatest power consumption. In the passive system, food and water input from above the water level would flow down into the bioreactor. This design allowed for continuous flow and least energy consumption. However, the bulk of this system would need to be strictly underwater, so we would have to look into waterproofing. #filtration #flow #gravityJune 16th
Focus: System Flow Decisions have been made! With flow method and battery selected, we move onto pumps.Entry:
Maneesh and Dylan made a presentation for discrete flow. The system seems to be complicated, as it involves pressure gradients and the use of feedback loops and modifiers to generate pressure equalization. Since simplicity is a top priority, we returned to continuous flow because it would be easier to implement and still fulfill the functional requirements. During further discussion, we did a back-of-the-envelope calculation for a continuous flow rate of water. It came out to be 0.03 milliliters per minute, which meant we needed a very precise, slow-acting pump. For the purpose of conserving energy, Dan found some low power pumps, including a $5 Chinese manufactured pump and a $20 500 GPH (gallons per hour) bilge pump. However, more research is required to find the optimal pump. We also thought about methods for introducing food into the stream. One idea was to use a worm-gear compressor to slowly push through our system. Chie presented candidates for our biosensor battery. We selected a 100Ah deep cycle gel cell battery, after listening to suggestions from several professors. Lydia and others discussed meeting with ECE professors to figure out the logistics of the circuitry component. We have a rough plan for developing the potentiostat, which is vital for measuring changes in potential, or signal produced by the bacteria when they detect toxins in the water. #flow #pump #battery #potentiostatJune 23th
Focus: Water Pump Honey, I shrunk the pump! Team is baffled by the micropump.Entry:
We scrapped the marine bilge pump because we found micropumps! They are so small and light that theoretically (and don’t quote me on this) you could swallow it and find it intact 3-5 days later in the bathroom. Most importantly, they fit the flow rate requirement and are low power. Chie calculated that the system with the micropump can run for a month exclusively off of the battery. Of course, this was very exciting news for the team! Afterward, we performed analysis on the battery dimensions--specifically weight and volume. We needed the numbers to fit the constraints of preliminary chassis designs. On a last note, here is a brief recapitulation. The general layout of operations has been established: a micropump will provide continuous fluid flow through the bioreactor; a compression device will introduce the liquid-based food source into the flow upstream of the bioreactor. Ultimately, the objective is to make a steady state biosensor that can run autonomously for 6 months. #micropump #battery #recapJune 27th
Focus: Electronics For realization of the biosensor, the Geek Squad discusses electrical components.Entry:
Wednesday is now designated meeting time for the electronic aspect of the system. At the start, Dan made a chart of broad objectives that were broken down into tasks. Objectives include circuitry build, implementation of microcontroller and data transmission. An electrical engineering major, Lydia was the most knowledgeable one as we looked for analog-to-digital converters (ADC) and microcontrollers. In order to send data wirelessly, we decided to go with transmission over a cell phone network. First, the electrical signal from the bioreactor would be sent to the microcontroller; the microcontroller would be connected to a cellphone, which would then broadcast the data to a remote location. Kelvin as the computer science guy was the prime candidate for developing an Android application that would act as the interface between the microcontroller and phone. #potentiostat #electronics #microcontroller #ADC #Android #phoneJune 30th
Focus: Food Containment; Design of Chassis Mm mm... talk about food and open grills.Entry:
Yesterday, the microcontroller for our entire system, the Arduino ADK, was the first item to arrive! Produced in Italy, it seems like a neat, little thing. While we glossed over the board, Lydia and Kelvin went over some details regarding data transfer from the board to an Android phone. After settling down, our first line of business was to finalize the method for storing the viscous yeast-rich food source. Although we initially planned to machine a PVC cylinder, the issue of pressure building up due to airtightness led us to consider IV drip bags instead. Simple enough, the transparent pouches would deflate as food was depleted and give a clear indication of how much food is left. On a different note, these last few days have been inundated with ideas for housing the equipment. The chassis is required to float on the water surface and withstand the impact of a log traveling downstream. We also voted to place the solar panels within the case, spurring the need for a transparent rooftop; desiccant would prevent the inside from fogging up. Several messy sketches later, we envisioned a cylindrical chassis: a semi-cylindrical ceiling that mirrors the base. The roof would be some type of polycarbonate bent into a semicircle fixed on either side by the thin aluminum or steel walls that would provide strength for the casing. Steel rods would . After accounting for weight, we thought it best to similarly incorporate the cheaper and lighter polycarbonate material into the base. Our design resembles a grill, with the top half opening up like a briefcase. The solar panels are fixed to the roof. There are two mid-level trays to attach the Arduino board, bioreactor, food and micropumps, and one lower tray for the battery. To prevent contamination and promote portability, everything except the battery is installed into the chassis before deployment. The reactor is fixed to a swiveling plate on the tray to minimize sloshing and disturbance when someone is carrying the case. Once at the site, a person would need to only do 3 things: place the battery into the case, move the case out into the water and secure it to an anchor. Ultimately, our tentative design is streamlined for simplicity and portability. #food #chassis #grill #deployment