3. Bio-Inspired Design of a Multi-scale Pass Band Frequency Sensor Using Local Resonance Phenomena

With growing interest in nanotechnology, the manufacturing industries for Micro-Electro-Mechanical Systems (MEMS) and Nano-Electro-Mechanical-Systems (NEMS) are constantly thriving towards extraordinary precision in the machining and etching tools. It is a common practice, during manufacturing, a set of instructions are provided to a manufacturing tool, by actuating them at certain frequencies to perform their respective tasks. Every different task (e.g. cutting nano-channels, drilling micro-holes, nano-welding etc.) has unique instruction with unique frequency input. In such cases, other than the desired frequencies, remaining possible frequencies in the system needs to be filtered or stopped. It is extremely challenging to avoid system noises electronically and select or actuate specific frequencies. Hence, in a noisy environment (e.g. fluctuation of temperature, external vibration etc.) it is extremely difficult to provide a unique frequency to a tool to perform a task precisely without having an uncertainty. In this study, we intend to propose a mechanical model to precisely sense, pass and actuate desired frequencies and filter unwanted input frequencies, which in turn will result a mechanical pass band sensor. Traditionally researches are interested in stopping undesired frequencies to pass desired frequencies through local resonance phenomena. However, if only certain frequencies are required, it is extremely difficult to filter all unnecessary frequencies by creating frequency band gaps. Hence, in this effort, bio-inspired logistic, adopting local resonator physics is employed by extracting the benefit of unique frequency sensing, mechanically. Human cochlea senses only sonic (20 Hz to 20 kHz) frequencies by filtering all other frequencies in the environment. Basilar membrane is the principal component of the human cochlea with logarithmically decreasing stiffness from its basal to apical end. Basilar membrane composed of series of thin micro beams attached to each other, where each beam holds unique bending rigidity and hence, capable of resonating at a particular sonic frequency. Similarly, in this study, to replicate the functionality of a basilar membrane, a discrete mass-in-mass (DMM) metamaterial model is proposed while using a complete different physics of local resonance. It is hypothesized that, systematic arrangement of such DMM cells can select of band of frequencies, predictively.