There are places on the earth that scientists want to study, but that study is difficult due to the danger involved in getting there. University of Washington researchers have created a potential solution that harnesses months to drop sensors into difficult to reach areas from the sky. The sensor attached to the back of the moth weighs 98 milligrams, which is about 1/10 the weight of a jellybean.
Once the sensor-laden moth is at its destination, scientists can send a Bluetooth command that would release the sensor and allow it to fall up to 72 feet and land without breaking. Once on the ground, the sensor would collect data on temperature and humidity for almost three years.
Researchers note this is the first time anyone has shown that sensors can be released from insects or tiny drones. Insects are the more likely candidates because they’re able to navigate narrow spaces better than a drone and can sustain longer flight. The sensor would be held on the drone or insect using a magnetic pin surrounded by a thin coil of wire.
To release the sensor, a wireless command would create a current through the coil to generate a magnetic field, which makes the magnetic pin pop out of place and sends the sensor falling. The design of the sensor puts the battery, which is its heaviest part, in one corner. Due to the weight being in that corner, as the sensor falls, it rotates around the battery generating additional drag force and slowing its descent.
Due to the design and the low weight of the sensor, the maximum fall speed is around 11 miles per hour, allowing the sensor to hit the ground safely. The process is envisioned to allow the creation of sensor networks in the study area. Scientists admit that they still have to develop a way to recover the sensor after the batteries have depleted, allowing them to be used in environmentally sensitive areas. The battery could one day be replaced with a solar cell to help alleviate power limitations from batteries.