By Dr. Cameron Chai
A team of researchers at the University of Massachusetts Amherst has invented a new adhesive device inspired by gecko feet. The device called “Geckskin” has the ability to hold objects weighing 700 lb on smooth surfaces such as glass.
"A card-sized pad of Geckskin can firmly attach very heavy objects such as this 42-inch television weighing about 40 lbs. (18 kg) to a smooth vertical surface. The key innovation by Bartlett and colleagues was to create a soft pad woven into a stiff fabric that includes a synthetic tendon. Together these features allow the stiff yet flexible pad to “drape” over a surface to maximize contact.
Photo: UMass Amherst"
Geckos weigh around 5 oz and have the ability to carry 9 lb vertically over walls. They can easily climb over slanted and backward-tilting surfaces. The research team including Alfred Crosby and Michael Bartlett at the polymer science and engineering lab, Duncan Irschick, functional morphologist, and other colleagues at UMass Amherst have found out the secret behind the phenomenal adhesive force of gecko feet.
The easily reversible adhesive force of the gecko’s feet is due to the combined action of various elements, such as its skin, bones and tendons. Earlier studies had concentrated on setae, the microscopic hairs on the gecko’s toes. The present study showed that the setae were not the reason behind the adhesive power.
The Geckskin device can adhere on smooth surfaces and has the ability to hold a force of around 700 lb. It measures about 16 sq.in and can be used to stick computers and televisions of up to 42” size. The device can be easily released from the wall with little effort and can then be restuck onto other surfaces, repeatedly. The adhesive does not leave any residue. The researchers integrated a soft pad and an adhesive and wove it into a stiff fabric. This enabled the adhesive pad to be draped over the required surface for maximizing the contact. This skin is then designed to form a synthetic tendon that has rotational freedom and stiffness. The researchers used polydimethylsiloxane (PDMS) and other easily available materials for making the adhesive pad. PDMS holds potential for usage as a durable, dry and low-cost adhesive.
The study has been published in the Advanced Materials online issue.