Thermal characterization of micrometric polymeric thin films by photoacoustic spectroscopy

Photoacoustic characterization of the mechanical properties of thin films

Narrow band photoacoustics ~laser ultrasonics! are used to characterize the properties of free-standing nanometer-sized thin films. Photoacoustic generation is achieved by use of a microchip laser which deposits pulsed laser energy in the form of a spatially periodic source on the structure. The resulting narrow band ultrasonic modes are monitored using a Michelson interferometer. By varying th...

Photoacoustic transients generated by laser irradiation of thin films

Irradiation of an optically thin layer immersed in a transparent fluid with pulsed laser radiation can generate photoacoustic waves through two mechanisms. The first of these is the conventional optical heating of the layer followed by thermal expansion, in which the mechanical motion of the expansion launches a pair of oppositely directed sound waves. A second, recently reported mechanism, is ...

Piezoelectric Polymeric Thin Films Tuned by Carbon Nanotube Fillers

Piezoelectric materials have received considerable attention from the smart structure community because of their potential use as sensors, actuators and power harvesters. In particular, polyvinylidene fluoride (PVDF) has been proposed in recent years as an enabling material for a variety of sensing and energy harvesting applications. In this study, carbon nanotubes (CNT) are included within a P...

Non-fouling thin polymeric films synthesized by PECVD

Polymeric films have been synthesized by a conventional PECVD technique at low temperature on COC substrates. Depending on the precursors chemistry and process conditions non-fouling property has been obtained which was correlated to chemical bonds similar to PEO/PEG bonds. The deposition process doesn’t involve any fragmentation of usual PEO/PEG precursors as mentioned in the literature but th...

Impedance Spectroscopy of Thin Films