Scientists is Korea are developing a new sound and motion sensor which could soon give people and buildings the equivalent of “Spidey sense.” This is a practical application of the discovery of how spider legs function in the real world. The new technology consists of ‘crack sensors’ or nanoscale crack junction-based sensory systems. These could be worn by people or placed on objects or structures and were inspired by a spiders’ crack-shaped slit organs. These organs are made up of the spider’s exoskeleton on the surface and a flexible pad within the gaps. It is these sensors on the spider’s legs which connects directly to the spider’s nervous system that the scientists have utilised.
The scientists can envisage almost endless possible applications of the new technology; from speech recognition and sound recording to sensing the earliest tremors before an earthquake. It could also be used as a medical monitoring application too.
The pads are highly sensitive to sound and vibrations, and act as the early warning system for spiders. This is the reason why a spider almost appears to sense when you’re going to swat it with your newspaper, but then escapes. So your tiniest of movements will trigger the spiders’ built-in sense alert system.
In a recent study that was published this Wednesday in the journal Nature, the researchers have detailed a remarkable example of biomimicry; The researchers have built a version of these slit-based sensors from a 20 nanometer layer of platinum on top of a viscoelastic polymer. By deforming the platinum layer to make cracks, which open to the soft polymer below, the scientists were capable of measuring the electrical conductance across the surface of their created sensor.
According to experts, there is a reason why this nano-crack sensor is so effective, it is to do with tiles.
Prof. Dr. Peter Fratzl of the Max Planck Institute of Colloids and Interfaces in Germany said, “I call it the virtues of tiling.” Fraztl was not involved in this study, but he has worked on research which laid the groundwork for the Korean team’s work. Back in 2009, Dr. Fratzl and Friedrich Barth of the University of Vienna published a paper on the spider’s slit organ. “We described the biological phenomenon and they took it and turned one of the aspects of it into a technical system.” The study’s lead author, Daeshik Kang, read Fratzl and Barth’s 2009 paper in Nature and proposed mimicking that geometry for an electro-mechanical sensing system.
Professor Mansoo Choi of the department of mechanical and aerospace engineering at Seoul National University, worked on the study, wrote in an email, “Our mimicked nano crack sensors can give ultra-sensitivity in electrical resistance, since cracks opening and closing can vary resistance significantly.”
This technology is still in the very early stages, so it will be a few years before we see a practical application of nano-cracked sensors. Mansoo’s team is hoping that “three-to-five years should be needed to be commercialized.”