Nine lessons from ‘clever’ nature that inspired photonics engineering

The great horned owl's eyes are among pheonomena from
nature that have helped inspire photonics engineering.

Spiders, fireflies, and pythons have all been responsible for inspiring solutions to challenges facing engineers working in light-based science and technology.

As Joseph Shaw, director of the Optical Technology Center at Montana State University, put it, “Nature has developed, very cleverly, some lessons on how to create the features that we desire in optical design.”

A highlight of the conference on Bioinspiration, Biomimetics, and Bioreplication at SPIE Smart Structures and Nondestructive Evaluation early each year in San Diego is a visit from an animal ambassador and handlers from the San Diego Zoo’s Centre for Bioinspiration. The center’s mission is to advance the creation and development of nature-inspired products and processes that benefit humanity, wildlife, and habitats. Past years’ animal visitors have included:

• Monty the Python [video 6:46], whose heat-seeking olfactory structures and hooked underside scales have helped inform engineering of thermal sensors and of mechanical propulsion systems for robotic and other equipment.
• Shaman the Great Horned Owl [video 12:56], whose large eyes are densely packed with receptors -- 1 million in each square millimeter, compared with 200,000 in the human eye – rendering the owl's daytime vision 6 times better and its night vision 10 times better, and providing ideas for improved optical displays.

A conference on The Nature of Light: Light in Nature chaired by Shaw and colleague Rongguang Liang of the University of Arizona College of Optical Sciences last August at SPIE Optics and Photonics offered more examples:

• Some insect wings have antireflective cone-like structures of a few nanometers that absorb virtually the entire visible spectrum, a team from the University of Namur (Louis Dellieu, et al.) reported, suggesting possible applications for camouflage.
• Another team at Namur (Annick Bay, Alexandre Mayer) has developed a firefly-inspired structure for improving efficiency of LED lighting, using observations from how the bioluminescent organ of the firefly functions.
• Using spiders, Bor-Kai Hsiung and other researchers at the University of Akron are studying how colors evolve to serve different functions, and how those colors are produced within a relatively simple system. They explored questions such as whether spiders use fluorescence as a mechanism to protect themselves from UV radiation, and what functions color serves for nearly blind tarantulas, outside of sexual selection.

In other recent research looking to nature for inspiration:

• At the recent SPIE/COS Photonics Asia conference in Beijing, researcher Min Gu from Swinburne University of Technology talked about biomimetic photonics inspired by a recent finding in the study of butterfly-wing scales. By mimicking the microscopic structures, researchers from Swinburne and Friedrich-Alexander Universität Erlangen-Nürnberg have developed a device smaller than the width of a human hair that could help make optical communications faster and more secure.
• Malte Gather of St. Andrews University explains how the DNA blueprint of fluorescent proteins in the cells of bioluminescent jellyfish [video 6:18] can be introduced into other organisms or structures, for example in micro lasers to speed up measurements being made by chemical sensors, and in future to create nontoxic cell markers for microscopy and add in disease diagnosis and treatment monitoring.
• A team from Pennsylvania State University is developing decoys to blunt the spread of tree-killing emerald ash borer beetles. Their larvae feed on the sap of ash trees, killing by depriving trees of nourishment. Entomology professor Thomas Baker teamed up with the research group of engineering science and mechanics professor Akhlesh Lakhtakia to replicate biological structures such as fly eyes and butterfly wings. The groups developed a decoy that visually replicates the female borer, enabling researchers to trap the males to decrease breeding and thereby larvae.
• Virginia Tech College of Engineering researchers have built a man-size, autonomous robotic jellyfish, a larger model of a previous robotic jellyfish built by the same team headed by Shashank Priya, professor of mechanical engineering. Jellyfish are attractive candidates to mimic because of their ability to consume little energy owing to a lower metabolic rate than other marine species, the researchers said. With no central nervous system, jellyfish instead use a diffused nerve net to control movement and can complete complex functions. "A larger vehicle will allow for more payload, longer duration, and longer range of operation," said Alex Villanueva, a doctoral student in mechanical engineering working under Priya.

More to think about as the photonics world gears up to observe the International Year of Light!