The Role of Metamaterials in a Sustainable Future
Our world is full of conventional materials that have limited uses and potential. We use plastic to strengthen glass windows, aluminum to prevent corrosion, and copper to conduct electricity, but their efficiencies as bulk materials may restrict their potential. To carry them beyond these limits, we are now realizing new limits by using metamaterial technology.
Metamaterials are a new class of materials that are pioneering a technological revolution that impacts almost every industry, particularly in clean technology. With minimal intervention, metamaterials are able to enhance existing products that may have already reached their efficiency capacity. Now we can overcome obstacles in the industry by using an entirely new technology.
Energy efficiency is an important topic for clean technologies that compete against fossil fuel-based energy alternatives. Where many sustainable energy sources are expensive, fossil fuel still is a relatively inexpensive and reliable source to our dependence on electricity. This dependence on electricity is not likely to change, but at least the sources for harvesting it are becoming greener. With metamaterials, these evolving cleantech solutions can aid replacing toxic elements with clean, sustainable, and efficient sources that reduce carbon emissions.
The word “meta” comes from a Greek word that means “to go beyond.” Although metamaterials use conventional materials such as metals and plastics, they act entirely different than their bulk materials do. Within a metamaterial are microscopic patterns that interact with light in unconventional ways. For example, metamaterials can block, enhance, or absorb light to provide a vast array of product applications including those in the cleantech industry.
What can they do?
Solar energy is one of the most promising clean technologies that is changing the world. It promises a long term energy solution. A remote island off the coast of Australia, for example, is now completely powered by solar energy thanks to Tesla’s micro grid. It’s not only a testament to the incredible improvements in photovoltaic panels since they were invented in 1839, but also to our ability to reduce our carbon emissions.
Until recently, solar panels were only expected to reach a theoretical limit of 33.7% in ideal circumstances (Shockley–Queisser limit). With metamaterials, we have the potential to absorb not only the light that directly passes into a solar panel, but also light that enters it from wide angles. Conventional methods use a sturdy structure that pivots to face the sun for maximum efficiency, but this may no longer be necessary. When light hits a metamaterial optimized for solar panels, it is redirected and absorbed instead reflecting away by the panel’s structure.
Light emitting diodes (LEDs) are the obvious lighting solution for residential use, however they offer limited brightness levels for other applications. In many cases, they can be up to 80% more efficient than a 60-watt incandescent bulb, But for applications that require higher brightness levels or “lumen output,” incandescent, halogen, or fluorescence lighting still dominate. Aiming for high brightness LEDs sometimes leads to reduced efficiency and still may not offer sufficient lumen output for industrial spaces such as warehouses or retail stores. With metamaterials, light has the potential to be extracted and redirected to improve lumen output and drastically expand the potential for LED applications.
Integrating metamaterials with clean technology means improved efficiency, reduced carbon emissions, and a brighter world. It’s part of a new technological revolution that can change how we use, interact, and benefit from light in any industry. Perhaps someday we will send metamaterial infused solar panels on spacecraft or use metamaterial LEDs to eliminate incandescent light altogether. With an optimistic outlook and a unified goal for a sustainable future, scientists are on the right track for a future that is filled with life-changing and sustainable cleantech.