Interdigital sensors and transducers

This review paper focuses on interdigital electrodes—a geo-metric structure encountered in a wide variety of sensor and transducer designs. Physical and chemical principles behind the operation of these devices vary so much across different fields of science and technology that the common features present in all devices are often overlooked. This paper attempts to bring under one umbrella capacitive, inductive, dielectric, piezoacoustic, chem-ical, biological, and microelectromechanical interdigital sensors and transducers. The paper also provides historical perspective, discusses fabrication techniques, modeling of sensor parameters, application examples, and directions of future research. Keywords—Dielectric measurements, interdigital sensors, non-destructive testing (NDT), sensor design, sensor modeling, spec-troscopy, surface acoustic waves (SAWs), transducers. I