Difference between revisions of "Team:Cornell/Design"

The hardware components of this multidisciplinary project were designed and implemented using many engineering principles. After consulting various hydroponic farmers, researchers, and distributors, we were able to tailor our product to meet their specific needs (see Practices). By using an iterative prototyping process, we modeled and tested our designs repeatedly and improved each time based our results. All the while, we aimed to develop an integrated system that can be easily utilized by our entire customer base.

Cornell iGEM’s OxyPonics system combines our biological components with a hardware implementation that ensures we use the full potential of our bacteria. Our system is composed of three major parts. The first part is our bacteria, which provides optical outputs based on the redox environment and produces antioxidants in response to light signaling. Next, our sensor, which reads those outputs and decides how to signal the bacteria to produce the right amount of antioxidants. Finally, we have created an online dashboard, giving users real time access and control over their farm’s oxidative stress environment. To see our final product, go to our Applied Design page.

The Product Development team utilized the IDEO design thinking process developed by the Stanford Design School. The process follows five steps: empathize, define, ideate, prototype, and test [1]. At the beginning of the design process, we first discussed the various options to consider such as what materials to use, how the bacteria would be incorporated into the hardware, and how this product can impact the world. We participated in a hardware accelerator program at Rev: Ithaca Startup Works and ultimately built our project in three phases: feasibility, proof-of-concept, and prototyping. After months of brainstorming, we decided to make a compact sensor unit utilizing our Wetlab’s engineered redox sensitive proteins to detect the amount of oxidative stress in the environment. Studies show that providing the right amount of oxidative stress to plants can increase growth by 5-15% [2]. Hydroponic farms currently do not utilize ways of measuring oxidative stress, giving us a potentially novel idea. To test feasibility, we interviewed professors, farmers, and companies, conducting over 40 interviews to discover our customers’ wants and needs. We were able to define a problem and proceeded to iteratively sketch ideas for our proof-of-concept. After prototyping, we brought our ideas back to our interviewees to receive feedback and improve our design, ultimately developing our OxyPonics project.

OxyPonics mechanical product consist of three main components. The first component is a central housing box. All electrical mechanisms and motors that power OxyPonics’s data gathering-and-response system are contained inside the water-tight box. The housing uses epoxy and 3D printed constructs to safely enclose all dry components of the product. The second component is a rotating light module controlled by servos, which consists of two lights. One light shines a 448 nm wavelength of light to activate the fluorescent protein [3] and the other a 576 nm wavelength of light to activate pDawn and produce enzymes to breakdown the oxidative stress [4]. The third component of the redox sensor is the mounted camera. This camera measures the fluorescence emitted by the bacteria’s fluorescent protein and sends the appropriate amount of pDawn activating light. Ratiometric algorithms use the camera’s readings to ensure the water surrounding a hydroponic plant stays at the optimal oxidative stress state. All three components can be attached to our designed railing system to minimize the number of cameras a hydroponic farmer may need. This railing system can capture real time data of each and every plant within an entire hydroponic bed.

We 3D printed several plastic models of the electronics housing, the camera mount, the servo mounts, and the Raspberry Pi mount using the Makerbot provided at Rev and the Rapid Prototyping Lab at Cornell University. The ArduCam 5 MP Mini Camera OV5647 1080p and light module were set up in the electronics housing. The waterproof box containing the electronic components of our product was machined by members of the team in the Emerson Lab at Cornell University. The box was designed to hold a piece of plexiglass on top to allow the fluorescence from the bacteria to reach the camera system and our wavelengths of light to activate the bacteria. All electronics and software were assembled and produced by the Product Development team.

1. How to Kick Off a Crash Course. (n.d.). Retrieved May 19, 2017, from https://dschool.stanford.edu/resources/gear-up-how-to-kick-off-a-crash-course
2. Schützendübel, A., & Polle, A. (2002, May 15). Plant responses to abiotic stresses: heavy metal‐induced oxidative stress and protection by mycorrhization | Journal of Experimental Botany | Oxford Academic. Retrieved October 24, 2017, from https://academic.oup.com/jxb/article/53/372/1351/644132/Plant-responses-to-abiotic-stresses-heavy-metal
3. Zhang, J. (n.d.). Fluorescent Proteins . Retrieved October 24, 2017, from https://www.einstein.yu.edu/research/facilities/facs/page.aspx?id=22638
4. Magaraci, M. S., Veerakumar, A., Qiao, P., Amurthur, A., Lee, J. Y., Miller, J. S., . . . Sarkar, C. A. (2014, December 19). Engineering Escherichia coli for light-activated cytolysis of mammalian cells. Retrieved October 24, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5264543/