Passive Cooling of a Micromechanical Oscillator with a Resonant Electric Circuit

Passive cooling of a micromechanical oscillator with a resonant electric circuit.

We cool the fundamental mode of a miniature cantilever by capacitively coupling it to a driven rf resonant circuit. Cooling results from the rf capacitive force, which is phase shifted relative to the cantilever motion. We demonstrate the technique by cooling a 7 kHz cantilever from room temperature to 45 K, obtaining reasonable agreement with a model for the cooling, damping, and frequency shi...

a New Resonant Converter Circuit for Reluctance

The purpose of this paper is to introduce a different type of converter circuit used to drive switched reluctance motors. It continues with detailed discussion on the resonant converter armed at minimizing or eliminating the transistors switching losses. Finally the drive has been tested on a disc-type reluctance motor for the perfomance and functionality.

Resonant coupling of a Bose-Einstein condensate to a micromechanical oscillator.

We report experiments in which the vibrations of a micromechanical oscillator are coupled to the motion of Bose-condensed atoms in a trap. The interaction relies on surface forces experienced by the atoms at about 1 microm distance from the mechanical structure. We observe resonant coupling to several well-resolved mechanical modes of the condensate. Coupling via surface forces does not require...

Excitation, detection, and passive cooling of a micromechanical cantilever using near-field of a microwave resonator

Nonlinear damping in a micromechanical oscillator

Nonlinear elastic effects play an important role in the dynamics of microelectromechanical systems (MEMS). A Duffing oscillator is widely used as an archetypical model of mechanical resonators with nonlinear elastic behavior. In contrast, nonlinear dissipation effects in micromechanical oscillators are often overlooked. In this work, we consider a doubly clamped micromechanical beam oscillator,...