Structural nanomaterials, sensors show promise but providers must prove reliability first
By Genevieve Oger
When artists’ drawings of space elevators built with carbon nanotubes started making their way onto the science pages of local newspapers a few years ago, it seemed like nanotechnology was on the cusp of revolutionizing space exploration and aeronautics. But today such dreams have, well, fallen back to Earth. With reality failing to match the grand expectations, aeronautic industry watchers have become a little more circumspect.
“Technologies flying in space are 10 years behind what is state of the art terrestrially,” said Thomas George, formerly at NASA’s Jet Propulsion Laboratory and a founder of CANEUS, a non-profit organization devoted to increasing the use of micro and nanotechnology in the aerospace industry. “In the 1960s and the Apollo years, space innovations were driving technology forward, but that’s no longer the case.” The main difficulty today, he argues, is that testing is much more expensive in space and that the high cost of airborne missions makes space agencies quite risk averse.
Despite this, the aeronautics industry is actively researching how it can harness the promise of micro and nanotech. And a few firms are managing to do so today.
Swiss-based Colibrys focuses on providing its customers with MEMS and MOEMS components and subsystems – specifically, motion sensors designed to be used in harsh environments to detect tilt, acceleration, inertia, shock and vibration. Such sensors can be used in missiles, drones, small civil aircraft or for other navigational purposes.
Colibrys has a staff of 110 in Neuchatel and another 150 in Houston, Texas. Its customers include British defense and aerospace company BAE Systems and French defense and electronics company Sagem, as well as other defense contractors.
Colibrys’ business has been growing 30 percent a year, in part because its products can be used by the military. “The process is trying to take technology that has been qualified in cars or industry, (and cause it) to be adopted by the military and then aeronautics,” said Sean Neylon, chief executive. “After that confidence building, the people who work in space will use it.”
Satellite companies are also experimenting with micro and nanotech solutions. European aerospace group Alcatel Alenia Space has been testing RF MEMS. They have the potential to improve communications between a satellite and its base by ensuring better quality transmission with less power drain. The company has taken part in different European-Union-funded research programs focused on the technology, but so far, it hasn’t been able to use it in their products.
“It will be a long time before we can use RF MEMS in commercial satellites, though I am confident they will be used one day,” said Augustin Coello-Vera of Alcatel Alenia Space. “Those customers want to see them in orbit for several years before they are used widely, so we must use piggy-back demonstrators,” he added, referring to the practice of testing new technologies by adding them as auxiliary payload.
Satellite makers whose customers are mostly non-commercial, such as Colorado-based Microsat Systems, have had an easier time integrating micro and nanotech innovations in their products. The company, which is under contract with the General Services Administration (GSA), the U.S. federal government’s procurement agency, has used micro and nanotechnology to build a 220-pound micro-satellite.
“We embedded the electronics and power storage of the satellite into a composite material, turning it into a multifunctional material,” said Mohan Misra, the company’s CEO. In addition, the solar panels that power the satellite were placed on light-weight plastic instead of silicon. “We also used micro and nanoscale devices and mechanisms,” Misra said. “Combining all these things, we were able to reduce the weight ten-fold.”
Generally speaking, the aeronautics business remains extremely conservative and risk averse, making it difficult for micro and nanotech applications to be integrated into new products.
This is even more so in the case of civil aircraft makers like Europe’s Airbus. Automobiles and trains might crash every day, but any commercial airliner accident or malfunction makes headlines around the world. “Currently, there exists no nanotechnology applications in our aircraft,” said Henrik Roesner, a structure engineer at Airbus. “But we expect that within the next few years, we will have some breakthroughs.”
Airbus is particularly interested in harnessing the power of micro and nanotech to assess the structural health of aircraft, much in the way the body’s central nervous system allows a person to feel the pain that causes him to give attention to a specific body part. For example, the company is exploring at the laboratory stage the idea of developing piezoelectric paint made of lead-zirconate-titanate nanopowder. On a plane, such a piezo-active surface could behave like a very precise sensor, capable of generating electric information about possible vibrations, defects or impacts on an aircraft surface.
Roesner stresses that micro and nanotech offers great promises, but that the aircraft industry operates in unique conditions – carrying human beings – and that puts extreme demands on qualifying new technologies. “The material really needs to be better,” he said. “And we need to ensure that the material will maintain these properties in extreme conditions and on a long-term basis.”