Smart materials & systems - Introduction
By Alan Hooper
The fusion of advanced materials with the power of information technology is providing designers with a new family of engineered materials and structures. By integrating sensors and actuators within a structural material, so called 'Smart Structures' can operate at the very limits of their performance envelopes and to their structural limits without fear of exceeding either. Categorised as 'sensory' or 'adaptive', 'smart' structures can provide maintenance engineers with a full report on their performance history, as well as the location of defects, whilst also counteracting unwanted or potentially dangerous conditions such as excessive vibration.
• Sensory structures are already making an impact on health and usage monitoring in the aerospace and civil engineering sectors, e.g. embedded fibre optic sensors can be used in applications ranging from aerospace and maritime to civil engineering.
• Adaptive structures with their ability to control shape and vibration response in real-time will have significant impact on application sectors ranging from adaptive aircraft wings and noise suppression to vibration resistant buildings and consumer goods.
'Smart' structures can be fabricated by integrating sensor and actuator materials within a host structural material. Examples of this technology include Sensory Structures containing fibre optic or piezoelectric sensors and Adaptive Structures containing piezoceramic, electrostrictive, magnetostrictive and shape memory solid state actuators. The aforementioned actuation materials are solid state, however smart fluids also have the ability to change properties given a suitable stimulus.
The dream, of course, is to integrate all this functionality at the microstructural or atomic/molecular scale to produce a truly 'smart material'. However, this is still some way off, even though the enabling technologies, such as nanotechnology, are under development.
For some companies that are involved with 'smart' sensory structures visit:
- Smartfibres - for descriptions of embedded fibre optic sensors in applications ranging from aerospace and maritime to civil engineering
- Smartec - for examples of fibre optic sensing in large-scale civil engineering structures
For more info on 'smart' adaptive structures visit:
- Active Noise Suppression - Ultraquiet, a commercial noise suppression structure for aircraft - includes an interactive demonstration
- Structural Control of Buildings - Japanese buildings constructed by the Takenaka Corporation incorporating structural control for wind and earthquake eleviation
- 'Smart' Consumer/Sports Goods - a brief description of 'Smart Skis'