California Institute of Technology

Philip X-l Feng

Michael Roukes

Michael C Cross

Matthew H Matheny

Rassul Bulatovich Karabalin

Luis Guillermo Villanueva Torrijo

Luis Guillermo Villanueva

Doubly-clamped nanowire electromechanical resonators that can be used to generate parametric oscillations and feedback self-sustained oscillations. The nanowire electromechanical resonators can be made using conventional NEMS and CMOS fabrication methods. In very thin nanowire structures (sub-micron-meter in width), additive piezoresistance patterning and fabrication can be highly difficult and thus need to be avoided. This invention shows that, in piezoresistive nanowires with homogeneous material composition and symmetric structures, no conventional and additive piezoresistance loops are needed. Using AC and DC drive signals, and bias signals of controlled frequency and amplitude, output signals having a variety of frequencies can be obtained. Various examples of such resonators and their theory of operation are described.

Electromechanical oscillators, parametric oscillators, and torsional resonators based on piezoresistive nanowires

A parametric feedback oscillator includes a resonator which has at least one transduction element and at least one electromechanical resonating element. The resonator is configured to accept as input a parametric excitation signal at a frequencyand to provide a resonating output signal at a frequency &#x3c9;. A cascaded feedback path in any electrically coupled cascade order includes at least one non-linear element, at least one phase shifter electrically, and at least one amplifier. The cascade feedback path is configured to receive as input the resonating output signal at a frequency &#x3c9;and configured to provide as output a feedback path signal as the parametric excitation signal at a frequencyto the resonator. A parametric feedback oscillator output terminal is configured to provide the resonating output signal at the frequency &#x3c9;as an output signal. A method of causing a parametric feedback oscillation is also described.

Parametric feedback oscillators

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Beachwood, OH, United States of America

Philip X-l Feng