Tiny Levers, Big Moves in Piezoelectric Sensors --Description for the Visually Impaired (back to video)
Text on Screen: National Institute of Standards and Technology (NIST)
As part of a large collaborative effort, NIST researcher Vladimir Aksyuk made computer models depicting a device made piezoelectric material PMN-PT.
Visual: Labeled "PMN-PT micromachined cantilever, the roughly t-shaped cross-section of a multilayered device appears on the screen. The long leg of the "t" is suspended from the bulk material like a diving board and is drooping slightly down. Color coding indicated areas of stress among the various layers of the device measured in megapascals, the top layer showing high stress in response to being stretched and the middle and bottom layers of the cantilever showing low and medium stress respectively.
The device is further peeled away and the constituent compounds are labeled. Silicon makes up the bulk, and a layer of lead titanate sits on top of the bulk and the cantilever. The bottom layer of the cantilever is a compound of strontium, rubidium and oxygen. The core of the cantilever is a layer of lead magnesium niobate and lead titanate.
Text on screen: Low voltage giant piezo response induces mechanical motion.
Visual: The cantilever begins to wag up and down, simulating the effect of a low voltage passing through the device. The stresses on various parts of the structure change as the cantilever moves.
Text on screen: Because piezoelectric materials translate external applied forces into electric charge, researchers hope to develop more sensitive sensors and harvest energy from as yet untapped sources of vibration, such as walking, to power devices.