Caterpillar catwalk: IR LED fashion

Skip to Navigation

Ezine

  • Published: Jan 8, 2019
  • Author: David Bradley
  • Channels: Infrared Spectroscopy
thumbnail image: Caterpillar catwalk: IR LED fashion

Following caterpillar tracks

Infrared light-emitting diodes have been stitched into special suits to allow biologists to study how soft creatures that lack articulated joints, such as the larvae of moths and butterflies, commonly known as caterpillars, can move. Frame capture from Levy video Also: thumbnail: By pondhawk - https://www.flickr.com/photos/38686613@N08/5015652133/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=27359110

Infrared light-emitting diodes have been stitched into special suits to allow biologists to study how soft creatures that lack articulated joints, such as the larvae of moths and butterflies, commonly known as caterpillars, can move.

Guy Levy Scientists of Tufts University and colleagues have created a designer suits for a caterpillar to help them understand how these creatures get around. Specifically, the team has investigated the tobacco hornworm caterpillar (Manduca sexta) using six strands of thin copper wire attached to the caterpillar’s back and along one side of its body. Other strands are at head and tail and at each of the caterpillar;'s four "pro-legs", its unjointed and stubby leg-like structures that help the caterpillar grip different surfaces. At the end of each wire is a 0.3 square millimetre infrared LED.

Levy, is a postdoctoral researcher in Barry Trimmer's laboratory and enthuses how studying the locomotion of soft animals, is fascinating. He points out that unfettered by bony joints or rigid exoskeletons, soft-bodied caterpillars are capable of extraordinary flexibility, enabling an enormous range of motion that allows them to perambulate over, in and around seemingly endless types of surface in their search for food and ultimately a place to pupate and undergo metamorphosis into their adult form.

Reflecting on markers

The research will not only help us understand some of the most ancient of terrestrial creatures, but also offer insights into how we might mimic their motions in robotic devices that side-step the usual articulated or wheeled devices. Such robots might be made collapsible and capable of multidimensional movement.

Trimmer has studied insect locomotion for decades, Levy joined his team some two and a half years ago and immediately began adapting Vicon cameras and software for motion capture of caterpillar locomotion. Vicon is a motion capture technology that has been used widely in the video games industry to track human movement using infrared cameras detecting retroreflective markers worn on clothing and then to analyse the movements. In the gaming industry the analysis is then used to create more lifelike animation, similar technology is used in animation for cinema and television.

However, adapting the technology for caterpillars was not easy, Levy points out, admitting that there were times when he thought it might not be possible at all. One barrier was the shiny, reflective cuticle of the caterpillar's body, which outshone, the tiny, reflective beads the team used at first as their movement markers. It was only when they thought to use an emissive marker rather than a reflective marker that the project metamorphosed into something more enlightening.

Caterpillar cakewalk

Levy soldered the IR LEDs jewellery wire to create his first haute couture caterpillar suit. The first LEDs tested were too cumbersome for the larvae but once they used miniscule 0.3 millimetre square, LEDs they were well on their way to a Vicon analysis of caterpillar cakewalk. A suited caterpillar gets to walk on a treadmill that keeps it in the frame of their IR-tracking camera. Custom software then analyses the way in which the IR markers move as the caterpillar does its workout. Levy presents details to the SICB meeting in Tampa, Florida in January 2019. The next step will be to analyse caterpillar locomotion over sticky and slippy surfaces and slopes.

Related Links

SICB Tampa Meeting 2019 January: "Society for Integrative and Comparative Biology Annual Meeting"

Article by David Bradley

The views represented in this article are solely those of the author and do not necessarily represent those of John Wiley and Sons, Ltd.

Follow us on Twitter!

Social Links

Share This Links

Bookmark and Share

Microsites

Suppliers Selection
Societies Selection

Banner Ad

Click here to see
all job opportunities

Most Viewed

Copyright Information

Interested in separation science? Visit our sister site separationsNOW.com

Copyright © 2019 John Wiley & Sons, Inc. All Rights Reserved