Deformations in stretched surface mounted ceramic strips for sensor applications

• Published in: Microelectronics international 2011-01, Vol.28 (3), p.19-23
• Main Authors: Gschohsmann, Walter, Nicolics, Johann, Suhir, Ephraim
• Format: Article
• Language: English
• Subjects: Acoustic wave devices, piezoelectric and piezoresistive devices; Applied sciences; Approximation; Ceramics; Deformation; Design engineering; Design. Technologies. Operation analysis. Testing; Electric properties; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Finite element analysis; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Integrated circuits; Mathematical analysis; Mathematical models; Microelectronics; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductor research; Sensors; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Strain; Stress-strain relationships; Strip; Studies
• ISSN: 1356-5362; 1758-812X
• DOI: 10.1108/13565361111162585

Purpose - The purpose of this paper is to present a most accurate analytical model suit for the prediction of the elastic displacements in a ceramic strip for sensing longitudinal deformations. Accordingly, the objective of the analysis given is to develop a physically meaningful and simple-as-possible stress-strain model for an elongated strip attached to a thick-and-stiff substrate.Design methodology approach - Today's advanced strain gage designs intended for measuring deformations and related physical characteristics use sensitive elements manufactured as ceramic strips. The output signal depends to a great extent on the ability to measure and to adequately interpret the induced elastic displacements in the strip, as the global electric resistor is coupled strongly to the strain field in the sensitive layer. The dependence of the strain on the thickness of a strip is calculated using an analytical 2D stress-strain model using a shear tension applied at its interface with the substrate and zero-stress at the opposite face as boundary conditions. All necessary considerations and calculations to develop the model are discussed.Findings - A significant result is the gradual reduction in the deformation depending on the layer thickness. Applying the model combines easy numerical effort with an expressive approximation.Originality value - The developed model can be used in the analysis and physical design of the structural elements of the type in question, not necessarily in the field of strain gage and sensor engineering.