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We demonstrate high quality-factor 1.5 mm diameter batch-fabricated microcrystalline diamond cylindrical resonators (CR) with quality-factors limited by thermoelastic damping (TED) and surface loss. Resonators were fabricated 2.6 and 5.3 µm thick in-situ boron-doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. The quality-factor (Q) of as-fabricated CR's was found to increase with the resonator diameter and diamond thickness. Annealing the CRs at 700 °C in a nitrogen atmosphere led to a three-fold increase in Q, a result we attribute to thinning of the diamond layer via reaction with residual O2 in the annealing furnace. Post-anneal Q exceeding 0.5 million (528 000) was measured at the 19 kHz elliptical wineglass modes, producing a ring-down time of 8.9 s. A model for Q versus diamond thickness and resonance frequency is developed including the effects of TED and surface loss. Measured quality factors are shown to agree with the predictions of this model. [ABSTRACT FROM AUTHOR]

We present the development of millimeter scale 3D hemispherical shell resonators fabricated from the polycrystalline diamond, a material with low thermoelastic damping and very high stiffness. These hemispherical wineglass resonators with 1.1 mm diameter are fabricated through a combination of micro-electro discharge machining (EDM) and silicon micromachining techniques. Using piezoelectric and electrostatic excitation and optical vibration measurement, the elliptical wineglass vibration mode is determined to be at 18.321 kHz, with the two degenerate wineglass modes having a relative frequency mismatch of 0.03%. A study on the effect of the size and misalignment of the anchor and resonator's radius variation on both the average frequency and frequency mismatch of the 2θ elliptical vibration modes is carried out. It is shown that the absolute frequency of a wineglass resonator will increase with the anchor size. It is also demonstrated that the fourth harmonic of radius variation is linearly related to the frequency mismatch. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the design and experimental verification of a new class of piezoelectric aluminum nitride (AlN) resonator with checker-patterned electrode architecture for mass sensing applications. The mass sensitivity of the developed sensor is analytically derived and confirmed with FEM simulations and experimental results. The results show that a 773MHz resonator has mass sensitivity of 175.42μm2/ng and detection limit of 18.7ng/cm2. The developed sensor has an obtained mass sensitivity of 2–3 times higher than that of state-of-the-art mass sensors and provides high potential for developed piezoelectric transducers for mass sensing applications. [Copyright &y& Elsevier]

A correction to the article "Hemispherical wineglass resonators fabricated from the microcrystalline diamond" that was published in the 2013 issue is presented.

Thin-film microcrystalline diamond micromechanical resonators with mechanical quality factor limited by thermoelastic dissipation in the diamond film are demonstrated. Surface micromachined double ended tuning fork resonators were fabricated from in-situ boron doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. Time-domain thermoreflectance measurements show thermal conductivity of 110 W m-1 K-1 for heat transport through the thickness of the diamond film. Measurement of the quality factor of resonators spanning a frequency range 0.5-10 MHz shows a maximum Q = 81 646 and demonstrates good agreement with quality factor limited by thermoelastic dissipation using 100 W m-1 K-1 for the in-plane thermal conductivity of the diamond film. [ABSTRACT FROM AUTHOR]

A high performance and cost effective biosensor is designed using a radial contour-mode disk resonator (RCDR). This sensor measures tiny biological mass attached on a disk vibrating at a high frequency, producing high quality of output signal. A series of analysis and simulation models is developed to predict the mass sensitivity, dynamic stability, and motional resistance of the RCDR biosensor with given geometry and signal input. In order to decrease motional resistance while keeping the fabrication cost low, a layer of dielectric material is deposited within the capacitor gap. In designing the RCDR biosensors, we employ Type I, II, and III robust design approach to design a device that is insensitive to various types of uncertainty associated with the fabrication processes and analysis models. A mathematical construct, error margin index, is employed for this robust design. Traditional optimization and robust design approaches are separately formulated, solved, and compared. From the design results, we observe that the RCDR is a promising bio-sensing device compared to the existing ones. [ABSTRACT FROM AUTHOR]