Geckos Inspire New Method to Print Electronics on Complex Surfaces

Geckos are masters at sticking to surfaces of all kinds and easily unsticking themselves, too. Inspired by these lizards, a team of engineers has developed a reversible adhesion method for printing electronics on a variety of tricky surfaces such as clothes, plastic and leather.

Researchers from Northwestern University and the University of Illinois at Urbana-Champaign designed a clever square polymer stamp that allows them to vary its adhesion strength. The stamp can easily pick up an array of electronic devices from a silicon surface and move and print them on a curved surface.

"Our work proposes a very robust method to transfer and print electronics on complex surfaces," said Yonggang Huang, Joseph Cummings Professor of Civil and Environmental Engineering and Mechanical Engineering at Northwestern's McCormick School of Engineering and Applied Science.

Huang, co-corresponding author of the PNAS paper, led the theory and design work at Northwestern. His colleague John Rogers, the Flory-Founder Chair Professor of Materials Science and Engineering at the University of Illinois, led the experimental and fabrication work. Rogers is a co-corresponding author of the paper.

Key to the square and squeezable polymer stamp are four pyramid-shaped tips on the stamp's bottom, one in each corner. They mimic, in a way, the micro- and nano-filaments on the gecko's foot, which the animal uses to control adhesion by increasing or decreasing contact area with a surface.