Adhesive Hairs on Dock Beetle Footpad (Image 2)

light microscope image taken at 50x magnification showing the measurement of single hair attachment forces from the footpad of a dock beetle (Gastrophysa viridula). Thousands of fine adhesive hairs are found across the feet of these beetles, allowing them to climb across smooth surfaces, such as a glass window pane or the flat surface of a leaf without needing their claws to hold on. In order to measure the attachment forces of a single hair, an experimental set up was developed using a fine glass cantilever (only 20 micrometres in width). This was lowered onto a single hair and then detached, with the resulting deflection recorded under high magnification. The forces measured from each hair are only a few hundred nanoNewtons; one millionth of the force required to lift an apple. (Date of Image: 2006-2011) [Image 2 of 4 related images. See Image 3.] Credit: James Bullock, University of Cambridge