Flexural zero-space waveguide arrays for waves in thin-elastic plates

The optimal confinement and compact configuration of waveguide arrays are essential for information transfer in wave systems. Within this context, the concept of zero-space waveguide arrays (ZSWA) emerges as an important class of waveguides, eliminating the need fora bulky cladding layer. This unique feature enables the stacking of multiple waveguides with a nominal zero-spacing, pushing the boundaries of conventional waveguide array designs. In this work, we delve into the realm of flexural waves, which presents a dual nature by sustaining both propagating and evanescent solutions. We delineate the impracticality of classical 'fiber waveguide' configurations due to the evanescent-to-propagating conversion inherent to flexural waves. Subsequently, we introduce a proposal to extend the concept of ZSWA into the domain of flexural waves. This nontrivial extension is achieved by harnessing various obstacle parameters such as height, clamped conditions, inhomogeneity, among others. Our investigation not only unveils the complexities of propagating and guiding flexural waves in thin-elastic plates but also offers a paradigm shift in the design of elastic waveguide arrays. By embracing minimal spacing through the utilization of ZSWA principles and incorporating obstacle variations, our study provides afresh perspective on the efficient design of waveguide arrays tailored for flexural wave propagation.