Modelling a surface acoustic wave based remotely actuated microvalve

We present a normally closed, remotely actuated, secure coded, electrostatically driven active microvalve using passive components. This is carried out by utilizing the complex signal processing capabilities of two identical 5 × 2-bit Barker sequence encoded acoustic wave correlators. An electrostatically driven microchannel, comprising two conducting diaphragms as the top and bottom walls, is placed in between the compressor interdigital transducers of the two correlators. Secure interrogability of the microvalve is demonstrated by finite element modelling of the complete structure and the quantitative deduction of the code dependent microchannel actuation. Furthermore, the influence of the excited acoustic modes of the correlator on the microchannel deflection is investigated to optimize the microvalve design. (Some figures in this article are in colour only in the electronic version)