Surface acoustic wave (SAW) devices are used in many distinct application areas, which include electronics, microelectromechanical (MEMS) sensors or even microfluidic lab-on-a-chip (LoC) devices. The electrode geometry usually exhibits a narrow frequency band response – this can be directly utilized in radio frequency filters or oscillators. As the wavespeed of the acoustic wave propagating on the surface of a material is extremely sensitive to changes in material properties, such as temperature, pressure or mass loading due to foreign substances, SAW sensors can be designed for these modalities. Deformation and elongation of a cantilever structure changes propagation delay between a set of transducers – thus an accelerometer is realizable. Surface waves can be coupled into fluid-filled microchannels generating forces; a promising application for lab-on-a-chip devices.

2019 is over and 2020 is here! OnScale saw a lot of new features added in 2019. Let’s take a look at five of our favorites.

We recently presented a webinar on Nonlinear Explicit Structural Analysis with OnScale Cloud Engineering Simulation. During the webinar we discussed the difference between implicit and explicit methods and the theory powering the nonlinear transient explicit core solvers of our software. We thought we would provide an overview of dynamic analysis and answer the most fundamental question here:

In our previous blog post, How to Assign Mechanical and Electrical BCs to Array Structures we showed you how to apply boundary conditions (BCs), calculate arrays, request outputs from the solver, calculate timestep by calling PRCS and set up the execution.

In a recent blog post, How to Build Arrays in OnScale we discussed how to build and control the size of the array structures using parameters. In this post we will look at how to assign mechanical and electrical boundary conditions (BCs) to this model and set up an execution loop to run the model on the cloud.

Ultrasonic phased array testing is a powerful non-destructive testing (NDT) technology which is growing rapidly.

Time of Flight Diffraction is a reliable method of non-destructive ultrasonic testing used to look for flaws in welds. In Time of Flight Diffraction (TOFD) systems, a pair of ultrasonic probes reside on opposite sides of a weld-joint or area of interest. A transmitter probe emits an ultrasonic pulse, which is captured by the receiver probe on the opposite side. In an undamaged part, the signals picked up by the receiver probe are from two waves: one that travels along the surface (lateral wave) and one that reflects off the far wall (back-wall reflection). When a discontinuity such as a crack is present, there is a diffraction of the ultrasonic sound wave from the top and bottom tips of the crack. Using the measured time of flight of the pulse, the depth of the crack tips can be calculated automatically by trigonometry. This method is more reliable than traditional radiographic, pulse echo manual UT (Ultrasonic Testing) and automated UT weld testing methods.

In the previous two blog posts the physical basis of piezoelectricity and the main groups of materials were presented, focusing on the selection of a material for a specific purpose. In this blog post we discuss in what configuration piezoelectric materials can be used and illustrate some example device structures.

In the previous blog post a grouping of piezoelectric materials was given into three categories: crystalline structures, engineered perovskite-like ceramics, and polymers. In this blog post a comparison of these groups is provided to aid the reader choosing a suitable material for a specific application.

In this first blog post of the piezoelectrics series, a brief overview is provided on the fundamentals of the phenomenon. Piezoelectric materials allow conversion of energy from the mechanical domain to the electrical domain and vice versa. They can be used to create various sensors or actuators: applied periodic electrical signal can result in the generation of ultrasonic waves for imaging purposes; stresses, such as observed for a cantilever suspending a mass in an accelerometer can be translated to electrical signals.