I-Corps: Photophoretically levitating platforms for atmospheric sensing and communications

Harvard University, Cambridge MA

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is the development of lightweight atmospheric platforms that require no moving parts or onboard power to loft payloads useful to climate research, telecommunications, and national security. Currently, conventional craft must carry fuel or batteries, which limits their payload capacity to be allotted to applications. The proposed technology may be outfitted with sensors for different atmospheric properties (e.g., pressure, temperature), which are key proxies for climate change and surface weather. These devices may be a valuable tool for climate researchers and practical monitoring and mitigation of global warming. Similar uses of these devices could benefit the exploration of Mars. Commercial and defense communications need higher bandwidths and a wider variety of unmanned aerial vehicles (UAVs). The military in particular needs covert and secure data transmission pathways. These devices may be used as telecommunications networks, relay points for sensitive information, and/or platforms for microscale sensors and cameras. Deploying this technology could, therefore, advance national security and prevent technological surprise. This I-Corps project is based on the development of ultra-lightweight devices that can self-levitate indefinitely in Earth’s and Mars’s atmospheres without onboard power or moving parts. The proposed devices are made of ultra-thin, nanofabricated structures that generate lofting via photophoretic levitation. This passive mechanism turns the sun’s radiative energy into a gas flow through the structures, producing thrust. The architecture of these devices allows the bulk of their payload capacity to be allotted to applications, an advantage over conventional craft that must carry fuel or batteries. Each device will have a payload capacity of a few 100 mg in Earth's mesosphere, enough to loft telecommunications and remote sensing hardware while station-keeping over a fixed point on the ground. Arrays of lofted devices are designed to interface with each other to achieve data rates greater than the sum of the individual devices. Further research into the materials science and gas physics underpinning these devices may expand the current understanding of the photophoretic force broadly. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.