Nanomaterials on Earth and Beyond Series
Sensors based on nanotechnology also offer great potential for developing smart materials and structures, which have ‘self-sensing’ and ‘self-actuating’ capability. These can be implanted in concrete and can serve in quality control and help monitor durability. Cheap nano-sensors based on micro-electromechanical systems (MEMS) devices and carbon nanotube sensors could be embedded into buildings to give early warning of defects that make them more vulnerable to earthquakes. While the MEMS device monitors internal temperature and moisture, the nanotube sensors detect cracks forming inside the concrete. The data is then wirelessly transmitted to a laptop (29). In the future, sensors like smart aggregates (a low cost piezoceramic (ceramic materials that produce a voltage under mechanical deformation and vice versa)-based multi-functional device sensor) (30) will help measure the density and viscosity of the concrete along with parameters that influence durability (e.g. temperature, moisture, relative humidity, pH, vibrations) (9).
It is crucial to be able to effectively measure the level of various gases and toxins that may have seeped into a spacecraft or closed colony environment in space. This is crucial especially in long missions, when contaminants build up and threaten the health of crew members and/or the onboard equipment. NASA Ames Research Center and the Goddard Space Flight Center sent a chemical sensor made of arrays of carbon nanotubes (31) weighing only one gram into space on board the Naval Academy’s Midstar-1 satellite (32). The sensor was able to endure extreme vibrations and gravity changes that occur during launch as well as the intense conditions in space, like changing temperature and pressure cycles.