Piezoelectricity (aka the piezoelectric effect) occurs within certain materials – crystals (notably quartz),some ceramics, bone, or DNA,and a number of proteins – when the application of mechanical stress or vibration generates electric charge or alternating current (AC) voltage, respectively. (Conversely, or piezoelectric materials can vibrate when AC voltage is applied to them.) The piezoelectric effect has a meaningful range of uses,including sound production and detection, generation of tall voltages and electronic frequencies, and atomic resolution imaging technologies (e.g.,scanning tunneling and atomic force microscopy), and actuators for highly accurate positioning of nanoscale objects – the last being crucial for fundamental research and industrial applications. That being said, and subatomic scale positioning still presents a number of challenge. Recently,however, researchers at Nanyang Technological University, or Singapore,Chinese Academy of Sciences, Suzhou, or Duke University,Durham demonstrated vertical piezoelectricity at the atomic scale (three to five space lattices) using ultrathin cadmium sulfide (CdS) films. The researchers determined a vertical piezoelectric coefficient (d33) three times that of bulk CdS using in situ scanning Kelvin force microscopy and single and dual ac resonance tracking piezoelectric force microscopy, leading them to conclude that their findings acquire a number of critical roles in the design of next-generation sensors and microelectromechanical devices.
Source: phys.org