Smart Materials - Essay Example

Download file to see previous pages Certain materials are responsive to changes in electric field or magnetic field such as Piezoelectric materials or Magnetic Shape Memory Alloys; while others are responsive to changes in temperature, light or even pH value.
The scope of this paper is to introduce four such smart materials namely, Piezoelectric materials, Magnetic Shape Memory Alloys, Halochromic materials and Chromogenic Systems. These smart materials would be discussed in the paper along with their practical usage and limitations.
Piezoelectric materials are smart materials that generate voltage when force is applied on such materials. The word ‘Piezo’ is a Latin term that means to press (How it works, 2003). In this manner, such materials are able to change their proportions when force, typically uni-axial compressive force is applied. One is able to identify piezoelectric materials as they produce voltage with the application of force or stress. Another identifying factor is the ability to change shape or become deformed once force is applied. Some examples of Piezoelectric materials are Quartz, Barium Titanate, Lead niobate and potassium sodium tartrate.
The initial usage of this device was found during the Second World War as they were used in SONAR devices. Commonly such materials are used in electro-mechanical devices including speakers and microphones. In microphones, Piezoelectric materials detect audible frequencies. They are also used in welding to serve various purposes such as welding inflexible thermoplastics, metal micro-bonding, steam welding sheets, insertion of metal into plastic etc. They are also used in hydrophones to monitor the heart and the circulatory system (Kutz, 2002).
While the usage of Piezoelectric materials is quite widespread, they are not without their limitations. ‘The most obvious limitations are associated with non-linearity, hysteresis, creep, depoling, electrical breakdown, Curie temperature’ ...Download file to see next pagesRead More