Inspired by the ease with which gecko lizards can move on almost any sur­face, researchers at North­eastern Uni­ver­sity, the Korea Insti­tute of Sci­ence and Tech­nology and Seoul National Uni­ver­sity hope to repro­duce prop­er­ties found in the gecko’s footpad for appli­ca­tions ranging from adhe­sives to robotic move­ment and navigation.

The team, led by Ashkan Vaziri, assis­tant pro­fessor of mechan­ical and indus­trial engi­neering at North­eastern, and Myoung-​​Woon Moon, of the Korea Insti­tute of Sci­ence and Tech­nology, cre­ated nanoscale and microscale pat­terned sur­faces with adhe­sion and fric­tion prop­er­ties sim­ilar to that of the gecko footpad.

The inno­v­a­tive method­ology, pub­lished online and in the aca­d­emic journal Soft Matter, could lead to the devel­op­ment of a “smart” adhe­sive that adapts to envi­ron­mental stimuli, such as a curvy sur­face or a rough edge.

The gecko footpad’s unique struc­ture and func­tion make it one of the most effi­cient adhe­sion sys­tems found in nature,” said Vaziri, who also directs Northeastern’s High Per­for­mance Mate­rials and Struc­tures Laboratory.

Gecko toes are cov­ered by mil­lions of hair-​​like struc­tures called setae, each of which is five microm­e­ters in size — smaller than a human hair. The ends of the setae are tipped with hun­dreds of spatula, which bend and con­form to the sur­face on which the gecko is moving. These prop­er­ties help geckos move robustly on vir­tu­ally all ver­tical and hor­i­zontal surfaces.

The research team designed and cre­ated a series of micropil­lars, or hair-​​like struc­tures, and exposed them to ion beam radi­a­tion. The radi­a­tion tilted the micropil­lars, resulting in a dual-​​surface area with unique adhe­sion and fric­tion properties.

Through a series of exper­i­ments, the team found that the micropil­lars had qual­i­ta­tively sim­ilar fric­tion prop­er­ties and func­tion when com­pared to the gecko footpad.

If equipped with micropil­lars, small high-​​tech robots [for research or mil­i­tary appli­ca­tions] might be able to climb with speed, pre­ci­sion and accu­racy on uneven, slip­pery sur­faces,” said Vaziri.

The tech­nology also could lead to a new gen­er­a­tion of smart adhe­sives that are equipped to hold strong bonds with any sur­face, he said.