DailyTech has run across a number of interesting devices usually developed for the sole reason of fighting diseases like cancer. Many of them use nanoscale particles created from simple and metamaterials alike. Some worm their way directly into a cell to cause its destruction via outside influences, while others simply hook themselves to tumorous growths and bathe them with pharmaceuticals designed to destroy the diseased cells.

A pair of researchers -- one from the California Institute of Technology at Pasadena, the other from Graduate Aerospace Laboratories -- have developed a new tool that could be used to destroy cancer cells. Though the device uses metamaterial science, it involves no injections, drugs or otherwise invasive techniques.

The technology Alessandro Spadoni (GAL) and Chiara Daraio (CITP) have harnessed is a mixture of metamaterial science and sonic wave generation. Known as an acoustic lens, the device can be thought of as similar to an ultrasound scanning machine, but many times more focused and, if need be, many times more powerful.

What separates the machine from a standard sonic scope is the design of the lens itself. Spadoni and Daraio's lens is a metamaterial composed of an array of steel spheres, 21 tall and 21 deep. The array is what the device uses to focus normal sound waves into a solitary wave, which can be delivered with pinpoint accuracy up to a few centimeters deep into tissues. By changing the spacing between the steel spheres, they can control the pulse of the emitted waves, creating sound bullets or successive "pings" for sound/ultrasound scanners.

To imagine how the device works, picture 21 Newton's Cradles all stacked on top of each other. To produce the solitary wave, the top and bottom rows are compacted closely together while in the inner rows, the spheres hang slightly separated. To produce the wave, a high energy pulse is first sent through the upper and lower rows, followed by a delayed pulse going from the outer to inner rows. The high energy pulse of the outer rows hits the medium first, followed in succession by the lower energy pulse of the inner rows in something of a C shape. This staggered pulse from outside to inside focuses all the energy towards the center of the solitary wave now traveling through the medium.

The technology could be harnessed for sonically destroying diseased or dead tissues without harming the surrounding cells, breaking up the various stones that can form in organs in the body, or at much lower powers, as an easily focusable and highly mobile sounding wand for sonic scopes.

The duo's release, titled "Generation and control of sound bullets with a nonlinear acoustic lens," can be found at the Proceedings of the National Academy of Sciences website. The original Phys.Org source has a short video showing how the sound pulses travel through the array to create a solitary wave in a medium.