Electricity powers the world. It powers stop lights at an intersection, it powers cars, it even powers the very device displaying this text. However, conventional methods of attaining energy, specifically with the use of electricity are not attainable in certain circumstances and use finite resources that will eventually be scarcely left. With this proposition in mind, scientists have been developing new ways of harnessing energy through other means, one of them being with the use of the piezoelectric effect in its various applications.
The piezoelectric effect is quite simple in its fundamentals. There are certain materials, specifically crystals that have such a molecular structure in which they lay in a neutral state and do not create an electrical current but will both respond to physical stress by creating an electrical current and responding to an electrical field with physical expansion or compression of the crystal. There are many such materials that exist, the most well-known of them being quartz which was initially used with electronic applications. Synthetic piezoelectric materials have been created to increase certain attributes of natural substances and enhance them. One of these is PZT (lead zirconate titanate) which has a higher voltage than quartz at the same levels of applied stress. It is used in ultrasound transducers for loudspeakers, microphones and many other devices. Barium titanate is another piezoelectric material with a reputation for durability and is used as a thermistor.
The applications for these materials can also be much more complex and ingenious than the simple conversion between mechanical force and electrical disbalance in a crystal. As an example, in quartz watches, electricity is sent through the crystal causing it to vibrate at a precise and unchanging frequency which is over 32,000 times a second. Using this value, scientists have been able to translate a certain number of oscillations from the crystal into seconds which is picked up by a circuit inside of the watch. With this, the watch does not need to rely on the strength of the battery to dictate the length of a second and regardless of the strength, the crystal will vibrate at the same frequency.
As technology moves towards the future, applications of piezoelectricity hope to be broadened towards things such as wireless sensor networks in hospitals, helicopters, trains, and many other possibilities where traditional battery systems or thick electrical wiring are not possible to use. They may even be used under roads in order to power traffic lights with use of vibrations from cars. Even in a world where all seems grim and fuel and power sources are being rapidly depleted at an unsustainable rate, new technology still brings hope.