Ultrasonic refer to sounds produced by an object vibrating at a frequency higher than the human ear can hear. This frequency ranges from 20 kHz to any frequency but usually caps at 100 khz. However, one ultrasonic device managed to reach 25 GHz. These devices are used in medicine and even in the industry. In medicine, ultrasonic scanners have been developed based on the principle that they are a pressure wave with an extremely short wavelength. It can be shown that a wave is only affected by an object, which is larger than it wavelength. With this concept, it was used to develop a sort of x-ray on images inside a mother’s womb.
Since x-rays cannot be used because of its possible side effects on the baby inside, it was not used. Instead ultrasonic scanners where developed since they were just pressure waves and do not have an effect on the baby’s health at all. Furthermore, ultrasonic scanners are also used for diagnosing the condition of the patient’s organs. A prospected application, as well is ultrasonic surgery which aims to use the ultrasonic wave to remove tumors which results to a bloodless surgery. Ultrasonic waves have also entered the industry which involves welding, cutting and heating plastics. This has the principle of letting an ultrasonic wave fall on two pieces of plastic stuck closed together. Since ultrasonic wave is a pressure wave it causes the molecules of the objects to agitate and vibrate. With increased vibration comes increased temperature and thus the objects will melt, thereby welding the two objects together. One application of ultrasonic which is widely known, are ultrasonic cleaners. Their function is to blast away dirt from things like jewelry, laboratory glassware and watches by propagating a 30 kHz wave inside a liquid. This creates small bubbles to form and implode with the release individual pressure waves that give the force to remove the dirt.
Posted 2011-01-29 and updated on Jan 29, 2011 8:43pm by crisd