Initially part of a school project, we conducted user interviews with biologists working to conserve the leatherback sea turtle and identified a need: better nest temperature monitoring. Because the gender of sea turtle hatchlings is dependent on the temperature of the nest in which they are laid, monitoring nest characteristics is critical to conservation as global temperatures continue to rise. Researchers typically measure temperature with thermocouples, essentially two wires that produce a voltage proportional to the temperature.

Thermocouples are cheap and accurate, but they can get lost, buried in the sand, and are labor intensive to use. Currently, a biologist must walk up to the physical nest location every time they wish to take a single temperature reading, a process that can take three hours in peak nesting season.

Our sensor costs approximately $17 dollars and saves money by using common electronics components, a homemade 3D-printed case, and a coin cell battery.

Here’s how our sensor works: biologists currently patrol the beach at night looking for female turtles that come out of the ocean to nest. As the turtle is laying her eggs, the biologists will turn on our sensor and toss it into the nest.

The sensor is spherical in shape to prevent puncturing the shells of the turtle embryos—while still being strong enough to support the pressure of the sand covering the nest. The sensor will take measurements until the baby turtles hatch—about 65 days—after which the biologists will excavate the nest as part of a routine research procedure and recover the sensor.