Smart textiles are textiles that are able to sense stimuli from the environment, to react to them and adapt to them by integration of functionalities in the textile structure. The stimulus as well as the response can have an electrical, thermal, chemical, magnetic or other origin. The extent of intelligence can be divided in three subgroups:
- Passive smart textiles can only sense the environment, they are sensors.
- Active smart textiles can sense the stimuli from the environment and also react to them, besides the sensor function, they also have an actuator function.
- Finally, very smart textiles take a step further, having the gift to adapt their behaviour to the circumstances.
So two components need to be present in the textile structure in order to bear the full mark of smart textiles; a sensor and an actuator. Smart textiles can contribute to protection and safety in three ways: they are able to detect conditions that signal increased danger; they prevent accidents by sending out a warning when hazardous conditions have been detected; in the case of serious threats, they can react by providing instantaneous protection. An important benefit of smart textiles in protective applications is that the textile can react when necessary, in a passive way or by active control mechanisms.
Smart textiles can be aesthetic and performance enhancing. Aesthetic examples include fabrics that light up and fabrics that can change colour. Some of these fabrics gather energy from the environment by harnessing vibrations, sound or heat, reacting to these inputs. The colour changing and lighting scheme can also work by embedding the fabric with electronics that can power it. Performance enhancing smart textiles are intended for use in athletic, extreme sports and military applications. These include fabrics designed to regulate body temperature, reduce wind resistance, and control muscle vibration – all of which may improve athletic performance. Other fabrics have been developed for protective clothing, to guard against extreme environmental hazards, such as radiation and the effects of space travel.
All smart materials involve an energy transfer from the stimuli to response given out by the material. They are integrated and complex materials.They have the ability do some sort of processing, analyzing and responding. Even they can adapt to the environment. They can be described as textile materials that think for themselves. They got full ability to change themselves depending on — temperature, pressure, density, or internal energy—will change. The amount of energy transferred to make this change is determined by the properties of the material. This relationship between the amount of energy required and the degree of the specific change governs the behavior of all materials, including smart ones. In technical, high performance and conventional textiles materials, the properties scale the relationship between state change and energy transfer is not a complicated. It is straight forward. If they get energy or any stimuli from the outer environment they do not do any change on it .They just resist it or absorb it.
Smart textile fabric are mainly made from materials ranging from traditional cotton, polyester, and nylon. At present, however, fabrics with electrical conductivity are of interest. Electrically conductive fabrics are produced by deposition of metal nanoparticles around the woven fibers and fabrics. The resulting metallic fabrics are conductive, hydrophilic and have high electroactive surface areas. These properties render them ideal substrates for electrochemical biosensing, which has been demonstrated with the detection of DNA and proteins.
