Equipment in the field of biology is outdated. Team Basilisk was tasked to update the technology to help advance the research of DNA changes in reptiles. Small alterations in DNA can cause changes in an species development but it can be hard to determine just how these changes effect their movement. This means that precise experimental results are extremely important to understanding the relationships between genetic structure and performance. Outdated methods can stand in the way of such results. There is a distinct demand in research for a testing device which can accurately capture the specimen’s speed in a more natural environment than traditional laboratory settings.
Team Basilisk was asked by Dr. Feldman, who works for the Biology Department at the University of Nevada, Reno, to design and build a method of studying the movement of lizards and snakes when injected with Tetrodotoxin (TTX). The specimen’s response to the TTX (which is highly poisonous when exposed to humans) exposure is the key to this experiment. This toxin is commonly found in: Gastropod mollusks, eggs of horseshoe crabs, Newts, the skin of Atelopid frogs, skin and viscera of porcupine fish, balloon fish, globefish, blowfish, toadfish, sunfish, blue-ringed octopus, and some salamanders. (Some are pictured below with the TTX molecule; (http://emedicine.medscape.com/article/818763-overview)). Dr. Feldman injects the snakes with TTX and studies the effects since garter snakes are commonly resistant to the toxin. This knowledge offers an opportunity for numerical measurement when the snake is injected with the toxin, which may cause; fatigue, stress, and some normal reactions. In order to determine their coordination, speed, and overall performance it must be observed in the field in addition to the laboratory environment. The greatest challenge in collecting useful data is testing in the field. Research is currently limited to laboratory tests without modern, transportable, or durable tools.
The Reptile Racetrack project is meant to create a functional method of tracking various forms of movement of any reptile under observation. The methods of studying reptiles require that the project emphasize: transportation, a selection of the movement readings, ability to adjust the width where the specimens will be observed, and easy methods of collecting data. Current conditions are outdated for new testing methods. The previous device and electrical systems are decades old which makes the data transfer limited. The current state of research equipment in this field is not up to standard for modern science.
In order to meet the needs of our sponsor, Dr. Feldman, the Reptile Racetrack must meet all previous design specifications. To this end, Team Basilisk has broken down the project into three subsystems: mechanical, electrical, and transportation.
The mechanical subsystem concerns all the physical components of the track. These include the material selection, fabrication, and overall construction of the racetrack. In order to meet the weight, ruggedness, chemical resistance, and long life requirements, High Density Polyethylene (HDPE) has been selected. While it has a high density, HDPE excels in all other criteria necessary. Additionally, its material is easier to machine which makes it an easy task to reduce its weight by removing some volume. This will be done by carving channels into the underside of the horizontal field, reducing its weight by half.
For the following paragraph, refer to the figure below. T here are four sections of this HDPE, each one meter long(1) creating a four meter long track, will be connected using similar hinges seen at (2) and stabilized using brackets (3) when fully horizontal. There will be two adjustable tripod legs (4) to support this field, allowing for a variable height along with two monopod legs (5) to help stabilize and keep the field horizontal. This will also allow for any researcher to adjust the height to a comfortable weight specifically for them. Additionally, two sets of walls will accompany the field forming a track for the specimens to follow. These will be mounted on either side of the track where one wall can be moved to adjust the width (6) and the other wall is stationary and houses the sensors (7). On top of the field there will be AstroTurf that was cut to fit the field. This allows the snakes to get traction to move while the material is also able to withstand chemicals for cleaning which is an objective: durability
As far as the electrical system goes, each adjustable passive infrared (PIR) sensor will be connected to a separate pin on the Arduino Uno Microcontroller. This microcontroller will collect, analyze, and export useful data from the sensors. Additionally, a 5 volt output from the microcontroller will provide power to the sensors, along with resistors to regulate the current flow. Resistors will also be placed on the wires going from the sensors to the pins, but are not shown in order to differentiate the lines on the diagram. This is all shown in the picture below, as a simple circuit diagram.
Simple Circuit Diagram of the power, sensors, and resistors that regulate flow
The last section that needed to be considered was the ease of transportation which due to the unforeseen weight issue of the High Density Polyethylene, this had to be looked at by a different angle. With the new fold up design pictured below partnered with a dolly, Velcro straps, and a duffel bag for the tripod legs, Dr. Feldman or any other researcher will have no problem transporting the Reptile Racetrack to and from the field.
Field folded up in an easy to transport manner.
Case for the electrical components to be easily transported.
Duffel Bag used to transport the monopods.
Hand Truck used to transport the field, wall pieces, duffel bags, and tripods.
Proof-of-Concept: As a proof of concept, Team Basilisk will focus on proving the effectiveness of linked sections and stability in the overall operation of the track. The model will consist of a single section of the four piece track. The proof of concept will be composed of the horizontal field, two adjustable walls, and two tripod supports. Constructing the proof of concept will involve cutting the desired geometry from high density polyethylene plastic (HDPE), creating an attachment section on the tripods, and assembling everything to form a whole track. Team Basilisk has decided that platform stability, wall adjustability, and overall modularity are the most important factors for testing. As such, the platform development will not demonstrate the future use of the sensors and electronic circuitry that will be incorporated into the completed project.
Engineering Analysis: The main areas that were measured in the engineering analysis were weight reduction and displacement of a heavy load. The initial design contained an unmanageable weight of 250lbs although it had nearly undetectable shifts under high loads. The displacement of the original design was .0097 inches. The proposed solution involved creating channels that would reduce weight and still be able to bare high loads through ribbed sections. The proposed channels were modeled on SolidWorks; an image of the channels can be viewed in the image bellow.
SolidWorks picture showing the channels cut out of the field pieces.
The final design contains two large channels through the underside of the field with a spine running down the middle and perimeter supports. The channels reduced the weight of the field by approximately 50% and the experience shifts to a 100 pound load which is equal to approximately 1/5 of an inch.The figure bellow shows the final design field with the FEA under a 100lb force.
Fabrication: Fabrication was completed as planned to reduce the weight, the field and wall sections were milled, and holes were soon drilled to accommodate the pins. These pins, along with latches on the outer walls and brackets, were designed to help stabilize the walls atop the field. Hinges were connected to the fields to ensure the portability of the field and walls. Additionally, a steel cylinder was welded to a plate which was fastened to the underside of the field. These pins and plates were used to mount the tripods and monopods to hold the entire racetrack upright.
When the final product came close to an end there were plenty of smiles to go around.
On the electrical side of the project, most of the work on the hardware was completed in a timely manner. As far as the software goes, work continued throughout construction. This allowed Team Basilisk to adapt to any different conditions the fabrication process would certainly bring. There was an approximate total of 160 feet of wire split between 8 sensor offshoots, a signal ribbon cable, power, and ground wiring. Twenty-four t-splices accomplished connections between each individual sensor and the relevant pins on the microcontroller. Finally, a grand total of 24 female crimp pins and 8 male crimp pins were crimped onto the ends of the wires, soldered, and housed in the necessary housing. The programming language used was the native Arduino software. This program compares the times registered at each sensor, and as such can be used to calculate velocities, positions, and accelerations. With the electrical portion complete, simple Velcro and clips attach the necessary hardware to the physical track itself.
The team working away on the electrical wiring.
Team Basilisk has successfully been able to meet all the requirements specified by the sponsor of the project. Through the machining of the HDPE, a lightweight, transportable, and adjustable field was created. Although the price of the project was kept low, with all labor being put in by Team Basilisk, budgets have been created for any manufacturing of the racetrack in the future. The adjustability of the walls and height allow for a comfortable table that adapts to many sizes of specimens and researchers. In addition, the programming achieved via the Arduino UNO, far exceeds what the previous racetrack was able to do. Above all, the weight has been reduced to a manageable amount, yielding highly transportable methods that was applied. Below is a SolidWorks video showing how the Reptile Racetrack is assembled.
The utmost thought has been put into the purpose of each part of the table and why the use different products are unnecessary. With all things considered, the Reptile Racetrack fully meets the needs of the sponsor, and does so in an exemplary fashion.
Live Reptile on the Final Prototype
Meet the Team:
Dante Affonso is currently a senior accounting and mechanical engineering student at the University of Nevada, Reno expecting to graduate with two Bachelors in Science degrees in Spring 2015. He is the treasurer for the UNRchers club on campus, an active member of professional co-ed engineering fraternity Theta Tau, and has played both football and rugby for the university. His current job is working for university as a teaching assistant for Statics. Furthermore, with his two undergraduate degrees he plans to advance his career in accounting and engineering.
Ashley is currently a senior mechanical engineering student at the University of Nevada, Reno expecting to graduate with a Bachelors in Science in Spring 2015 with an emphasis in Mathematics. She plans to then continue to pursue her Masters in Business Administration (MBA). She also hopes to pursue a Masters in Biomedical Engineering after her MBA. She currently works at International Game Technology as a Manufacturing Engineering Intern. Ashley is an active member of the Professional Co-Ed Engineering Fraternity Theta Tau.
Daniel is currently a senior mechanical engineering student at the University of Nevada, Reno expecting to graduate with a Bachelors in Science in Spring 2015. Additionally, he is obtaining a minor in mathematics, and hopes to procure a business degree in the near future. Furthermore, Daniel is an active member of the Professional Co-Ed Engineering Fraternity Theta Tau. Ideally, he would like to become an entrepreneur and establish an engineering firm.
Austin is currently a senior mechanical engineering student at the University of Nevada, Reno expecting to graduate with a Bachelors in Science in Spring 2015. When he’s not doing school work or coordinating for the ASME and UNRCHERS clubs, Austin likes to spend his time doing leather and metalwork. Austin has significant experience using and teaching SolidWorks, but particularly enjoys employing the project management skills he gained interning at Ebara Cryodynamics. When he graduates, he hopes to find a job managing projects for manufacturing.
Andres is currently an on-track first year senior mechanical engineering student at the University of Nevada, Reno expecting to graduate with a Bachelors in Science in Spring 2015. His interests include heat transfer and planes. Andres aspires to attain an officer position in the air force upon graduation with a career dedication to jet engine manufacture or testing.
Team Basilisk is eternally grateful to Dr. Feldman for sponsorship of this project, and Alyx Colburn, the team mentor, who was instrumental in establishing the structure needed to function effectively together. We would also like to thank Tony Berendsen for his continual support in the machine shop, and especially for opening it during off hours. We are especially grateful to fellow senior Kanin Prucksakorn for opening his home shop to teach us welding, Emi Hansen and her experience in SolidWorks, and grad student Andy Smith for quality checking our Arduino code.