Archive for the 'Biomimicry and Bioinspired Energy' Category

Nature Inspired Wave and Tidal Energy Technologies

Australian based BioPower Systems BioStream technology generates electricity from tidal currents and was inspired by the Thunniform locomotion exhibited by shark and tuna species.

Their BioWave technology generates electricity from wave energy and was inspired by the motion of underwater plants (think kelp fronds!) that are anchored to the sea floor.  Read more about both technologies here.

Similarly inspired, Carnegie Wave Energy Limited’s CETO wave power converter produces high pressure seawater from the power of waves that can then power a turbine for electricity generation.

“The beauty of these wave-power technologies is that they move with the power of the ocean rather than putting themselves in confrontation with it.”-Ocean Energy Council

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Guest Post: A Solar Powered Wasp by Daniel Arneman

If you asked a classroom full of students to name something in nature that is powered by the sun, you’d probably get a long list of plants, trees, and algae.  You MIGHT hear that cold-blooded reptiles also  capture energy from the sun to warm their bodies.

Odds are, though, your students will be surprised to learn that some wasps are solar powered, too!

Recent studies of the Oriental wasp revealed that it can actually make electricity by harvesting the suns rays as described here:

“Previously, entomologists noted that Oriental wasps, unlike other wasps and bees, are active in the afternoon rather than the morning when the sun is just rising. They also noticed that the hornet digs more intensely as the sun’s intensity increases.

The team determined that the brown shell of the hornet was made from grooves that split light into diverging beams. The yellow stripe on the abdomen is made from pinhole depressions, and contains a pigment called xanthopterin. Together, the light diverging grooves, pinhole depressions and xanthopterin change light into electrical energy. The shell traps the light and the pigment does the conversion.”

Isn’t nature amazing?

What’s even more amazing is that nature makes these buzzing solar panels using just a handful of common chemicals found in all forms of life: carbon, hydrogen, oxygen, nitrogen, etc.  It does the manufacturing with water-based reactions and at ambient temperatures and pressures.

Contrast that with the typical solar panel manufactured in the United States and abroad.  Though many are made from common and harmless silicon, the wafers must be processed at extremely high temperatures (3,450 degrees F!) to achieve the desired effect, consuming massive amounts of energy and resources.

Newer “thin film” solar cells are made from elements like copper, indium, gallium, and selenium – relatively rare and expensive metals that can be toxic to people.

Next time you sit down to a big salad, or bowl of vegetables, you can appreciate the fact that nature makes solar panels out of non-toxic compounds that are actually good for you.  Who would’ve guessed that a solar panel could taste delicious with Ranch Dressing?

 

Daniel Arneman, PhD, is an environmental analyst at the University of North Carolina at Chapel Hill.  Daniel works to measure and manage the campus’s carbon footprint and he also has a passion for learning about biomimicry.

Dye Sensitized Solar Cells include elements that emulate Photosynthesis

In an effort to make solar photovoltaic (PV) technology more affordable, scientists are looking for ways to capture the sun’s energy using pigment molecules that can be incorporated into glass or flexible, plastic solar cells.  Currently these dye-sensitized solar cells (DSSC) are not as efficient as silicon-based PV solar cells but “have higher overall power collection potential due to low-cost operability under a wider range of light and temperature conditions, and flexible application” (Ask Nature.org).

The steps of light absorption by a pigment molecule and subsequent creation of an “energized” or mobile electron is shared between the process of photosynthesis that occurs within a leaf and the mechanism of a DSSC.  Read more about how photosynthesis has inspired scientists to harvest solar energy using dye sensitized solar cells.

The Biomimicry Institute has a lesson plan for middle and high school students: Plant-inspired solar energy lab activity, where students can make their own dye-sensitized solar cells using berries.  This activity utilizes the Nanocrystalline Solar Cell Kit available for purchase from the Institute for Chemical Education (ICE).

The basic science behind the operation of a DSSC,  including a schematic diagram, is described by Kenneth Hanson, PhD, a chemist at UNC, in his  review of this Nanocrystalline Solar Cell Kit from ICE.

To take this a step further, scientists at UNC’s Energy Frontier Research Center are working to adapt dye-sensitized solar cells to produce chemical fuels, instead of electricity, just as plants use photosynthesis to convert sunlight into chemicals.  This process of converting sunlight into a fuel is referred to as artificial photosynthesis.

Need a primer on Biomimicry? Check out this TED Talk by Janine Benyus

Biomimicry in Action

Janine Benyus, is co-founder of the Biomimicry Guild and founder of the Biomimicry Institute, and in 2007 was honored as one of TIME Magazine’s International Heroes of the Environment.

 

Guest Post: Whale Power by Daniel Arneman

Just how does a fifty foot long humpback whale dive deep and then leap from the water to the delight and amazement of whale watchers?  Certainly the whale is powerful, but there may be some other secrets to this 40 ton acrobat.

Scientist Dr. Frank E. Fish (yes – that’s his real name) went shopping for a gift one day, and spotted a humpback whale sculpture that seemed unusual.  On close examination, he discovered the sculptor had gotten the subject all wrong, carving bumps and ridges into the front of the whale’s fin.

Fish questioned the shopkeeper, explaining that accepted engineering standards require a smooth leading edge to cut through air or water.  The shopkeeper defended the sculptor, a meticulous whale watcher, and assured Dr. Fish that the humpback does indeed have bumps on the leading edge of its fins.

Perplexed, Fish investigated further and found that those bumps, or “tubercles,” have a dramatic impact on how the fin cuts through water.  It may not be a mistake after all!

Think back for a moment to a childhood car trip, waving your hand and arm out the window to feel the air rush by.  You noticed that if you held your hand out flat, then angled it up slightly, you could feel the lift of the air pushing against the bottom of your hand.  Make the angle too steep, and your hand would “stall,” being pushed backwards instead of up.

That “stall angle” is extremely important in the field of fluid dynamics, and it must be important to the humpback whale, because over time, its fins evolved a series of tubercles that actually increase the stall angle.  Put another way, the tubercles allow the whale to cut more sharply into the water, while still maintaining its forward momentum.  No wonder they can leap above the surface!

What does all of this whale talk have to do with renewable energy?  Well, a lot actually.

A company called Whale Power has created a wind turbine with “tubercle technology” built into the leading edge of the blades.  Just like humpback whale’s fins, the blades have a steeper stall angle and better aerodynamics, allowing them to harness more wind energy than their smooth competitors.  They produce more power, can operate at lower wind speeds, and are quieter than other turbines in their class.

Tubercle technology is SO good that the US Naval Academy is testing whale-inspired tidal generators that capture the energy in the ocean’s tide.

So next time you’re outdoors and see a plant or animal with an odd shape or unusual behavior, ask yourself how it got there.  Chances are very good that it’s no mistake – something’s life depended on it!

Daniel Arneman, PhD, is an environmental analyst at the University of North Carolina at Chapel Hill.  Daniel works to measure and manage the campus’s carbon footprint and he also has a passion for learning about biomimicry.

Biomimicry database at AskNature.org

Browse the biomimicry database at AskNature.org to find examples of renewable energy technologies inspired by nature

AskNature.org provides a free, online, searchable database of “Nature’s genius organized by design challenge.” Use this database to find a strategy used in nature and learn about the application ideas associated with this strategy.  Each strategy is accompanied by one or more color photos as well as a list of references for further information.

For example, you can read about the strategy window plants, which have pillar-like leaves, use to enhance photosynthesis and how this design could inform more efficient photovoltaic cells.

How has nature inspired renewable energy technologies?

This will be the question addressed by this month’s posts.  I have also invited Daniel Arneman, PhD, an environmental analyst at the University of North Carolina at Chapel Hill to contribute posts this month.  Daniel works to measure and manage the campus’s carbon footprint and he also has a passion for learning about biomimicry.

Biomimicry (from bios, meaning life, and mimesis, meaning to imitate) is a design discipline that seeks sustainable solutions by emulating nature’s time-tested patterns and strategies, e.g., a solar cell inspired by a leaf.  The core idea is that Nature, imaginative by necessity, has already solved many of the problems we are grappling with: energy, food production, climate control, non-toxic chemistry, transportation, packaging, and a whole lot more. AskNature.org

Introduce your students to the concept and methodology of biomimicry and inspire them to seek designs in nature. Download curricula, PowerPoint presentations, games and more for free from the Biomimicry Institute upon completion of a short online registration form.

Try Function Junction, an outdoor learning activity where students match a function (e.g., moving water) to an object from nature that performs that function. The specified functions must be solved both in the biological and human technological world.  For this activity you could add functions like 1) capture sunlight or 2) catch the wind to get students thinking about how nature can inspire wind and solar energy technologies.

 



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