There are vast advantages in the realisation of a SAW device based microvalve in Micro Electro Mechanical Systems (MEMS) and Nano Electro Mechanical Systems (NEMS) such as secure, reliable and low power operation, small size, simplicity in construction and cost effectiveness. In this paper, a Surface Acoustic Wave (SAW) based microvalve that generates micro actuations for microfluidic and similar applications is presented. The microvalve is batteryless and can be actuated wirelessly. The security of the device is enhanced by using a coded SAW correlator that is integrated as part of the microvalve. A theoretical analysis of how the actuation mechanism operates is carried out and simulation results of the new microvalve structure are discussed. The ANSYS simulation tool is used to design and simulate the micro-valve structure. Characteristics of the microvalve actuator in terms of displacement for different operating conditions are also discussed.