Coupled determination of gravimetric and elastic effects on two resonant chemical sensors: Love wave and microcantilever platforms

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control ferroelectrics, and frequency control, 2005-02, Vol.52 (2), p.297-303
• Main Authors: Fadel, L., Zimmermann, C., Dufour, I., Dejous, C., Rebiere, D.
• Format: Article
• Language: English
• Subjects: Acoustic coupling; Acoustic devices; Acoustics; Biomedical optical imaging; Chemical sensors; Deposition; Devices; Engineering Sciences; Estimates; Exact sciences and technology; Frequency estimation; Fundamental areas of phenomenology (including applications); General equipment and techniques; Gravimeters; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Love waves; Micro and nanotechnologies; Microelectronics; Optical polymers; Optical sensors; Physics; Platforms; Polymer films; Resonance; Sputtering; Thickness measurement; Transducers; Ultrasonics, quantum acoustics, and physical effects of sound
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2005.1406555

The objective of this paper is to couple theoretical and experimental results from microcantilevers and Love-wave acoustic devices in order to identify and separate mass loading effects from elastic effects. This is important in the perspective of sensing applications. For that, a thin-film polymer is deposited on both resonant platforms. It is demonstrated that microcantilevers are essentially mass sensitive. They allow one to determine the polymer layer thickness, which is validated by optical profilometry measurements. Then, taking into account this thickness, theoretical modeling and experimental measurements with Love-wave devices permit one to estimate an equivalent elastic shear modulus of the thin-film polymer at high frequency. Results are interesting if one is to fully understand and optimize (bio)chemical sensor responses.