Cutting edge technology: Sound sharpens the blade

Finetuning a single-blade sonic paper-cutter as an energy-saving sharpening instrument

“…As illustrated in Figure 2, an AFG 3021B arbitrary waveform generator (Tektronix Incorporated, Beaverton, Oregon, United States) was used to generate a continuous signal at the resonance frequency with either a 5 V peak or a 10 V peak operating voltage, which was fed into an A-150 55-dB linear power amplifier (ENI Technology, Inc., Rochester, New York, United States). This signal was converted to ultrasound using the ultrasonic knife described by [7], coupled with matching circuits. The ultrasonic knife was clamped on a retort stand It is important to match the impedance of the source and load to maximise the power transfer from the source to the load, thus increasing the energy efficiency of the device.…”

“…Mondi Rotatrim 160C1E ENVIROWHITE 80 g/m 2 A4 paper (Mondi Limited, Melrose Arch, South Africa) was guillotined into quarters (equivalent to an A6 page size), and each quarter folded in half. The experimental sheet and cutting procedure used was the same as [7]. Eight experimental sheets were used for each of the unsonicated, sonicated and matching circuit experiments.…”

“…Innovation has brought about its use in imaging, surgery, cleaning, cell manipulation, food processing, amongst other applications [1]- [5]. An interesting application is the sharpening effect that ultrasound demonstrates on cutting devices by creating microrotations of the blade [6] or by applying the ultrasound vibration directly to a fixed blade [7]. This is particularly of interest since the cutting force could be reduced and the surfaces of the cut would be of higher quality [6]- [9].…”