Saving a winged drone from a nosedive

The small domes on a fountain drink’s lid that indicate the beverage type may one day save a drone from a nosedive. Patterns of these invertible domes on a drone’s wings could sense dangerous conditions and react in microseconds.

Researchers at Purdue University and the University of Tennessee, Knoxville demonstrated a metamaterial that uses its shape to learn to adapt to its surroundings.

Unlike living beings, autonomous vehicles lack ways to filter out unneeded information, which slows their response time to changes in their environment.

“Drones can’t use their full flight capability because there’s just too much data to process from their sensors, which prevents them from flying safely in certain situations,” says Andres Arrieta, a Purdue associate professor of mechanical engineering with a courtesy appointment in aeronautical and astronautical engineering.

Dome-covered surfaces that can sense their surroundings would enable a drone’s wings to feel only the most necessary sensory information. Because only minimal force is needed to invert a dome, forces below this threshold are automatically filtered out. A specific combination of domes popped up and down at certain parts of the wing could indicate to the drone’s control system that the wing is experiencing a dangerous pressure pattern. Other dome patterns could signify dangerous temperatures or an object approaching, Arrieta says.

Electronics save and retrieve images by encoding information as zeroes or ones. Because a dome can adopt only two states – popped up or popped down – these states can act like zeroes and ones to create spatial patterns for building associative memory.

When a level of force inverts a dome, sensors embedded into the flat part of a metamaterial sheet surrounding the dome detect the change in shape. An electrical signal then triggers a memory device called a memristor to make a record of the force and where it was detected on the sheet. With each instance of an inverted dome, the metamaterial learns to remember the pattern a force creates on its surface. Because the metamaterial keeps a record from inverted dome patterns as a single memory, a drone wing would be able to quickly recall a pattern associated with a dangerous condition.

The metamaterial can be manufactured with existing methods, so domes can cover a large surface area such as a drone’s wing. Arrieta anticipates that it will be possible to build a drone wing using this material design in the next three to five years.

This research is supported by the Defense Advanced Research Projects Agency, National Science Foundation, and Indiana Space Grant Consortium.

Purdue University

University of Tennessee, Knoxville