Autonomous Rolling Sensor Spheres Powered by Geothermal Energy
By placing phase-change materials inside spherical shells, thermal energy from magma-heated ground creates internal weight shifts that power continuous movement—without batteries or motors.
Watching a sphere roll itself up a volcanic crater rim, powered only by the heat beneath it, streaming real-time gas composition and temperature data while no human could survive there—the sphere moves like it's alive, pulsing with thermal energy.