A Hidden Spark: Piezoelectrics

From Wikipedia:

Piezoelectricity is the ability of some materials (notably crystals and certain ceramics, including bone) to generate an electric field or electric potential in response to applied mechanical stress. The effect is closely related to a change of polarization density within the material’s volume. If the material is not short-circuited, the applied stress induces a voltage across the material. The word is derived from the Greek piezo or piezein, which means to squeeze or press.

The first recorded, modern study of piezoelectrics took place in the 18th century. Carl Linnaeus and Franz Aepinus started with research of the pyroelectric effect, using various materials to generate an electric response due to temperature change. This research prompted Rene Just Hauy and Antoine Cesar Becquerel to posit a relation between mechanical stress and electric charges. Unfortunately, their experiments proved inconclusive, leading to a bit of a gap in experimentation.

In 1880, Jacques and Pierre Curie were able to actually demonstrate the direct piezoelectric effect. They used their knowledge of crystal formation and behavior to predict the behavior of various forms of crystaline structures. These substances included Rochelle Salt, sugar, quartz and tourmaline.

After these experiments, however, piezoelectrics was relegated to a laboratory curiosity. Various experiments were conducted from time to time, but given little serious study until World War 1.

The first practical application was in the creation of Sonar. Suddenly, piezoelectrics was the big thing, and vast resources were given the the study of the effect, and the creation and application of new techniques and materials. Perhaps the most significant such development was put to use in World War II, when a new form of crystal facilitated the development of a radio light enough to use in an aircraft.

Yes, piezoelectrics heavily influenced the outcomes of both World War I and World War II! Today, a great deal of the things we take for granted utilize the piezoelectric effect in one way or another. Radios, televisions, cigarette lighters, inkjet printers, diesel engines, and even gas-grill igniters, all contain piezoelectrics. Yet this remains one of the lesser-known sciences in America.

Japan has been the leading piezoelectric developer and manufacturer since the beginning. While America slapped patents on every development and carefully hoarded secrets, Japan’s scientists shared their knowledge and pooled their resources. Guess who won that battle?

Recently, the University of Michigan threw their hat into the piezoelectric ring with the development of tiny generators. Running off of random piezoelectric impulses, the generators could power watches, pacemakers or wireless sensors. The sources of this random electricity? Noise pollution. The vibrations from factory machinery, cars driving on bridges, people walking.

In the past, piezoelectric energy has been most efficient on a regular, patterned source of vibrations. UM’s generators, however, are able to run on the highly random, low-frequency, unstable energy that is around us every day.

DARPA (Defense Advanced Research Projects Agency), a government research and development agency, experimented with putting piezoelectric materials in soldiers’ boots and harvesting the electricity. Although this project was scrapped, due to discomfort and lack of appreciable effect, such things may become more feasible as we research the phenomenon more.

One under-addressed issue is the sustainability of producing and using the man-made piezoelectric substances. Environmental issues are often behind immediate, human concerns in science, and this is an angle that could shake up the entire field. If this is to be intensively studied, then the sustainability and environmental impact need to be studied with equal scrutiny.

The piezoelectric effect is a scientific goldmine. But where could it take us as Science-Fiction writers? To the moon, theoretically.

1.) As generators such as the ones created by UM are studied and improved upon, larger ones could be created, putting out more power. Cities could invest in dozens of these, and set them under their busiest streets, on their bridges, anywhere where heavy, randomized vibration is prevalent. Theoretically, these could be used to power massive air-filters, street lights, traffic lights and public accommodations.

2.) Trains, cars, boats and personal conveyances of all sorts could run off of a piezoelectric motor, once the science evolves from micro to macro.

3.) Piezoelectrics could become the science of the future. As the population and noise pollution increase, the demand for power, and the source of the randomized vibrations will increase exponentially. As with any hot resource or science, this could kick off an international race for supremacy, manufacture and control of piezoelectric materials and discoveries. Of course, this would most likely require cooperation among scientists, leaving America in a race to adapt or fall far behind to countries with established piezoelectric programs, such as Japan. (Espionage! Stealing secrets! Villains and terrorists using advanced techniques to screw up our energy grids!)

4.) If the world turns its view back to outer space (And really, unless something cataclysmic wipes our civilization out, it is only a matter of time!), the use of piezoelectrics could make all the difference in sustainable space communities that did not have access to other sorts of fuel. The input-output ratio would need to be extreme and self-perpetuating, but mere living could power communities. (Heartbeats, footsteps, laughter, clapping, drums, a community powered by voice, sound, energy and movement?)

5.) Earthquakes are a powerful source of vibrations and stress. As we see more and more massive earthquakes striking around the world, the question is, how can these be harnessed to produce something good? (Portable piezoelectric stations, earthquake chasers, triggering earthquakes for power, crust faults, cataclysmic natural disasters triggered by man.)

6.) Slavery. Here’s your dystopian usage, as surplus population is harnessed to giant piezoelectric machines. How they create this vibration is up to you!

7.) Like the idea of Steampunk, but want to write something a little more modern? Use the piezoelectric effect to power your story! Cleaner than Dieselpunk or Industrial Fantasy, yet quite workable for an advanced fantasy/alternative history culture.

We have only just begun to discover the possibilities of the piezoelectric effect. Depending on the environmental effects of producing the materials, is this our clean science of the future? Is it a way to utilize the massive waste and pollution from our cities? Or will it prove to be dirty, dangerous and expendable, like so many other ‘next-best-things’?

Only the future will tell.

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