Here we demonstrate a novel metal-organic thin-film encapsulation technique for resonant gas microsensors to efficiently filter out airborne particles which can negatively affect device performance. The gravimetric sensors are ZnO-on-silicon extensional mode resonators coated with a gas-sensitive material. Mass change caused by chemical reaction and/or physical adsorption can be detected throug...

Vibrating micro- and nanomechanical mass sensors are capable of quantitatively determining attached mass from only the first three (two) measured cantilever (suspended) resonant frequencies. However, in aqueous solutions that are relevant to most biological systems, the mass determination is challenging because the quality factor (Q-factor) due to fluid damping decreases and, as a result, usual...

Parametric resonance based mass sensing leads to increased sensitivity over other resonant methods. In this work, we present a frequency-tuning approach to measure mass change in an ultra-sensitive mass sensor. This scheme drives the oscillator using an electrical signal with fixed frequency and tunes the parametric resonance frequency to match the driving frequency by feeding back a dc offset ...

The need to design blast resistant civilian structures has arisen due to aggressor attacks on many civilian structures around the world. Achieving vibration and wave attenuation with locally resonant metamaterials has attracted a great deal of consideration due to their frequency dependent negative effective mass density. In this paper, metaconcrete, a new material with exceptional properties i...

Nanocantilevers have become key components of nanomechanical sensors that exploit changes in their resonant frequencies or static deflection in response to the environment. It is necessary that they can operate at a given, but adjustable, resonant frequency and/or static deflection ranges. Here we propose a new class of nanocantilevers with a significantly tunable spectrum of the resonant frequ...

abstract: the main aim of the vibration energy harvesters is to locally power autonomous devices such as wireless sensors. generally, power levels are low and the environmental benefit of the technology is to replace batteries rather than saving energy per se. piezoelectric vibrational energy harvesters are usually inertial mass based devices, where a cantilever beam with a piezoelectric outer ...

The characterization of physical properties of cells such as their mass and stiffness has been of great interest and can have profound implications in cell biology, tissue engineering, cancer, and disease research. For example, the direct dependence of cell growth rate on cell mass for individual adherent human cells can elucidate the mechanisms underlying cell cycle progression. Here we develo...

Distributed sensing of gas-phase chemicals using highly sensitive and inexpensive sensors is of great interest for many defense and consumer applications. In this paper we present ppb-level detection of dimethyl methylphosphonate (DMMP), a common simulant for sarin gas, with a ppt-level resolution using an improved capacitive micromachined ultrasonic transducer (CMUT) as a resonant chemical sen...