Based on friction tests of surfaces mimicking the textures evolved on frog, cricket and salamander feet
Technion Scientists Discovered a Way to Significantly Improve Shaving Process
Technion scientists discovered a way to significantly improve shaving process, following friction tests of surfaces mimicking the textures evolved on frog, cricket and salamander feet.
The research group led by Assistant Professor Michael Varenberg, the Head of the Tribology Laboratories at the Faculty of Mechanical Engineering, examined how the frog, salamander and cricket, the creatures that live in a wet environment, do not slip on wet surfaces. The surfaces mimicking biological textures were tested using a one of its kind device that was built by Prof. Varenberg’s research group. This device is capable of measuring the forces that develop between the contact surfaces, such as friction and adhesion, while working within a scanning electron microscope. This allows simultaneous high-resolution visualization of the behavior of surfaces in contact. “We use nature’s solutions as inspiration for the development of new surface engineering technologies,” explains Prof. Varenberg. “We do this in collaboration with biologists who provide us with information on the functions and structure of complex biological systems that we are trying to simplify and implement using technical means. This allows us to understand how things work in nature and also promote engineering.”
The scientists found that creatures living in wet environments improve their grip by draining the fluid out of contact using special channels that exist on the contact surfaces in their feet. So it happens that similar problem exists in modern safety razors. The rubber strip ahead of the blades is used to improve shaving by increasing friction needed for stretching the skin before the blades slide over it. The presence of the shaving lubricant on the skin reduces friction and therefore interferes with the skin stretching. To examine real safety razors, the researchers removed the blades and replaced the original strip of rubber, which is covered today by a series of small fins (fig. 1), with a rubber strip bearing a biomimetic hexagonal surface texture that they built based on an extensive examination of frog, cricket and salamander feet. “The surface we produced in the lab is twice more effective at increasing friction on the skin covered by shaving foam than the surfaces used in commercial razors,” explains Prof. Varenberg, who co-filed a patent on this discovery together with his graduate student Alexey Tsipenyuk. “Our surface also felt much more pleasant in touch,” adds Alexey, who performed friction measurements on the skin of his forearm (fig. 2). Alexey’s poster was recently chosen as one of the 3 top posters on the competition at the Russell Berrie Nanotechnology Institute (RBNI).
The paper describing this work is published by the Royal Society journal Interface. It can be found at http://dx.doi.org/10.1098/rsif.2014.0113
The Patent: CHM-1561: Razor blade assembly
The friction-providing material used for stretching the skin while shaving constitutes an important component of modern safety razor design. This invention proposes the use of bio-inspired textured surfaces (mimicking those which crickets employ to enhance friction) to increase skin stretching in disposable safety razor assemblies. Borrowing from nature’s millennia of evolutionary development, it is expected to offer better shave results than current razor designs.