Study finds how lizard tails are sturdy at regular times but detach easily when needed

Findings may lead to novel designs to solve adhesion challenges in robotics and prosthetics

<p>Several lizard species can rapidly shed their tails to distract and escape from pursuing predators, a trait called autotomy</p>

Several lizard species can rapidly shed their tails to distract and escape from pursuing predators, a trait called autotomy

Tiny structures made up of mushroom-shaped micropillars topped with ultra-small pores allow lizards to quickly detach their tails when needed, a new study has found.

The research, published on Thursday in the journal Science, not only sheds light on how the tails are sturdy at regular times but detach easily when needed, but may also lead to novel technologies with new bio-inspired design ideas that solve adhesion and quick-release challenges.

Several lizard species can rapidly shed their tails to distract and escape from pursuing predators, a well-studied trait called autotomy. However, the tail also serves important balance functions when the lizards move and jump, and need them to remain firmly in place at most times.

While earlier studies have described the segmented anatomy of the lizard tail, the quick-release mechanism which enables autotomy isn’t fully understood, say scientists including Navajit Baban from New York University Abu Dhabi in UAE.

Lizard (Hemidactylus flaviviridis) after tail shedding

In the study, scientists developed a new model of lizard tail detachment and release based on microscopy images of the broken ends of lizard tails from two species of the Gekkonidae and one species of the Lacertidae lizard family.

They gently amputated tails from the lizards and analysed the broken sections under a microscope.

Microscopy images showed that each lizard tail muscle break-off point consists of highly dense mushroom-shaped micropillars with ultra-small nanopores dotting the top of each. These sections work like plugs into sockets, and the tail tends to break off these points – called fracture planes.

Microscopy showed tail fracture plane consist of mushroom-shaped pillars with nanopores at their tops

Scientists also tested the forces at work and the functioning of the tail microstructures by building a bio-inspired model using micropillars made of the polymeric material polydimethylsiloxane along with nanoporous tops.

They found that the the tail’s structure consisting of deep crevasses between micropillars and other smaller potholes on their surfaces could slow the spread of an initial fracture on the tail.

Their new model suggests that these microstructures in the lizard tail allow for enhanced adhesion under tension, but when faced with a slight twist, the fracture plane cracks, and the tail can separate.

This microstructure, researchers believe, plays a key role in balancing self-amputation when under threat and keeping the tails intact, achieving the “just right” Goldilocks zone in tail connection that is neither too weak nor too strong for the reptile’s chance of survival.

“Thus, autotomy proves to be a successful survival tool in the natural world, and its prevalence in both plants and animals gives confidence that it may be useful for scientific and engineering applications,” Animangsu Ghatak from the Indian Institute of Technology Kanpur, wrote in a related commentary article on the study.

“Particularly in robotics, stealth technology and prosthetics and for the safe operation of many critical installations, an optimised link similar to the one at present at the lizard tail can go a long way in protecting and expensive component or device from an unforeseen accident or mishap.” Dr Ghatak, who was not part of the study, added.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

By clicking ‘Create my account’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in