Piezoelectric Direct Discharge: Devices and Applications

Abstract

The piezoelectric direct discharge (PDD) is a comparatively new type of atmospheric pressure gaseous discharge for production of cold plasma. The generation of such discharge is possible using the piezoelectric cold plasma generator (PCPG) which comprises the resonant piezoelectric transformer (RPT) with voltage transformation ratio of more than 1000, allowing for reaching the output voltage >10 kV at low input voltage, typically below 25 V. As ionization gas for the PDD, either air or various gas mixtures are used. Despite some similarities with corona discharge and dielectric barrier discharge, the ignition of micro-discharges directly at the ceramic surface makes PDD unique in its physics and application potential. The PDD is used directly, in open discharge structures, mainly for treatment of electrically nonconducting surfaces. It is also applied as a plasma bridge to bias different excitation electrodes, applicable for a broad range of substrate materials. In this review, the most important architectures of the PDD based discharges are presented. The operation principle, the main operational characteristics and the example applications, exploiting the specific properties of the discharge configurations, are discussed. Due to the moderate power achievable by PCPG, of typically less than 10 W, the focus of this review is on applications involving thermally sensitive materials, including food, organic tissues, and liquids.

Visualization of Activated Area on Polymers for Evaluation of Atmospheric Pressure Plasma Jets

“…In configuration E, a needle corona [ 46 ] was supplied with high voltage (HV) from the CeraPlas™F over a plasma bridge [ 47 ]. This HV causes an atmospheric air corona discharge on the tip of the needle electrode.…”

“…The configuration F, referred to as a plasma needle [ 48 ], consisted of the same needle electrode as in configuration E, but was operated in a gas flow of different gas mixtures [ 47 ]. In this study, the results obtained with argon as a plasma gas are presented.…”

“…The discharge configuration G produced a dielectric barrier discharge (DBD) with an active electrode being the HV tip of the CeraPlas™F. Configurations E, F and G are realized technically as replaceable modules for piezobrush ® PZ3 [ 47 ].…”

Multi-Device Piezoelectric Direct Discharge for Large Area Plasma Treatment

“…The plasma focusing can be avoided by the application of a dielectric barrier discharge powered by the PDD. Different configurations of the PDD-powered DBDs are described in [17]. The DBD configuration used in this example is known in the literature as floating electrode dielectric barrier discharge (FE-DBD) [29,30].…”

“…Recently, the operation of piezoelectric direct discharge (PDD) [16,17] as an APPJ was characterized [18,19]. The resonant piezoelectric transformers (RPT) [20] used for generation of the PDD, can be used in arrays for the increase of the treatment area and speed.…”