Georgia Heintz’s Work Log

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  • Post last modified:October 29, 2023
  • Reading time:16 mins read
  • Post category:Work Logs

9/17/23 – 9/23/23

  • Met with Dr. Brzeski and Dr. Wolfe of the Forestry Dept. and learned the following:
    • White-footed mice are the species of mice in Michigan that are most likely to be hosts for ticks carrying Lyme disease
    • Local tick hotspots include Chassell and Maasto Hiihto
    • Data from local tick reports can be seen on the Tick-Talk Dashboard
    • To administer tick repellent to small rodents, in the past, there have been experiments involving PVC pipes coated with tick repellent on the inside that gets onto to the animals’ fur as they pass through
    • Many types of bait, such as peanut butter and sunflower seeds, used to attract mice also entice larger animals, including bears, so it’s important for our tick repellent administration systems to be very durable
  • Primary design considerations at the moment include:
    • Use of externally applied versus oral tick preventatives
    • Whether sheet metal to reinforce the exteriors of the tick repellent administration systems is a viable option with our budget
    • Design of entry and exit doorways
      • One potential option would be to have an entrance with a door that springs up and closes when a mouse walks over it, similar to that of a Sherman trap; pictured on the left side below is a Sherman trap loaned to us by Dr. Wolfe and Dr. Brzeski
      • Another possible choice would be to use one-way doors, such as check valve doors; below on the right side is an image of the beginnings of a prototype door using a design created by Matthias Wandel

9/24/23 – 9/30/23

  • Designed a prototype of the tick repellent administration system with CAD
  • All CAD models were created using the open-source software FreeCAD
  • Tolerances to facilitate assembling the system and to allow space for hot glue between components were included in the CAD models
  • The first four images below depict the individual components of the tick repellent administration system, while the three images following those portray the assembly

10/1/23 – 10/7/23

  • Current aspects of the design for the Tick Repellent Administration System (TRAS) include:
    • The entrance overlay is nonessential for the functionality of the TRAS, so the base component should have the ability to operate as a check valve on its own
    • A weight sensor could be placed just after the entrance door to record the number of mice that pass through the TRAS, but it will need to be accessible after the TRAS is deployed so that its data can be retrieved
    • The TRAS must be robust so that it can endure the conditions of the environment in which it will be deployed
    • To administer tick repellent to mice that pass through the TRAS, sponges soaked in liquid tick repellent could be secured to both sides of the base via hook and loop strips
  • CAD models for the TRAS components were updated to reflect these design considerations:
    • The base now includes a pair of triangular prisms before each door, so both the entrance and exit doors will only open one way
    • Since the entrance overlay is not essential for the TRAS to function, it was not included in this design iteration so the essential components could be prioritized
    • Components can be fastened together with a total of eight M4 X 16 mm socket head cap screws and M4 nuts, so all parts will be removable to facilitate accessing and cleaning the inside of the TRAS
    • To further improve the accessibility of the inside of the TRAS, the top of the base component was removed and a detachable lid was designed
  • The first four images below reveal the CAD models of the components, while the ensuing three images show the TRAS assembly and are followed by an image of the 3D printed doors and hinges

10/8/23 – 10/14/23

  • Once again, the CAD models for the TRAS’s components were updated
  • The entrance overlay component was brought back in this design iteration and, as with the lid, will be able to be attached and detached to the base via M4 X 16 mm socket head cap screws and M4 nuts, allowing for entrance overlays with differently dimensioned openings to be swapped out in a TRAS as needed
  • To adjust the opening of an overlay, one must open trasOverlay.FCStd in FreeCAD, edit the dimensions in the sketch for PadOpening named SketchOpening, and close the sketch
  • Another noteworthy adjustment was to the design of the door, so it can now be printed flush to the printer bed
  • The first five images below show the updated TRAS components, followed by three pictures of their assembly, and the final image exhibits prints of the overlay, one door, and all four hinges

10/15/23 – 10/21/23

  • Ordered components that are expected to arrive next week, including a load cell sensor for detecting when mice walk across it in the TRAS and a real-time clock (RTC) module for obtaining the precise date and time each mouse is sensed
  • The load cell and RTC will be used in conjunction with an Arduino Nano, which will be powered by a 9V battery
  • Began writing the TRAS’s Arduino code
  • Created an OSF repository to make all essential files for this project accessible to anyone who wishes to construct their own TRAS
  • Printed the second TRAS door, as shown in the image below

10/22/23 – 10/28/23

  • Nearly all of the components ordered the week prior arrived, apart from the load cell sensor and the HX711 load cell amplifier module
  • Two custom connectors to allow the Nano, RTC, and load cell amp to interface were created
  • The image below depicts the Arduino Nano at the top, the 9V battery in the middle, the DS3231 RTC module at the bottom, and the pins to be soldered to the HX711 module on the left
  • The red/orange/yellow/black connector on the left wires the HX711’s VCC, SCK, DT, and GND pins to the DS3231’s VCC pin and the Arduino’s D3, D2, and GND pins, respectively
  • The unit of green/blue/red/black wires on the right connects the RTC’s SCL, SDA, VCC, and GND pins to the Nano’s A5, A4, 5V, and GND pins, respectively