Arnon Hirshberg

Optimizing the Dynamic Response of RF MEMS Switches using Tailored Voltage Pulses

This paper presents analytic modeling, simulations, and experimental validation of RF MEMS switch actuation using tailored voltage waveforms. This actuation scheme can eliminate impact bouncing during switch activation and can significantly reduce harmonic oscillations during switch release.

Electromechanical Sensing of Charge Retention on Floating Electrodes

It is demonstrated theoretically and experimentally, that charge on floating electrodes can be measured by its effect on the electromechanical response of an electrostatic actuator. Charged, electrostatically-floating electrodes can be used as a DC bias source or for memory storage. Charge on a floating electrode must be measured indirectly because any direct measurement (e.g. measuring the voltage of the floating electrode) would cause discharge.

A novel method for measuring the strength of microbeams

A novel method and test structure for measuring the strength of brittle microbeams is presented. The method does not require any measurement of forces or displacements. The test structure includes a microbeam that is wrapped over a curved side-wall by application of an unmeasured force. With the progression of wrapping, increasing tensile stresses are induced in the microbeam. When sufficiently high stresses are induced, the beam breaks. The failure stress is deduced by measuring the length of the remaining ligament of the broken beam. The method is demonstrated by measuring the strength of microbeams in bulk-micromachined test structures.

Direct Wire-Bonding to Silicon Devices Without the Use of Metallic Layers

We present a novel method of direct wire-bonding of Silicon MEMS devices that does not require any metal bond-pads. We demonstrate that the strength and the conductivity of direct wire-bonds are comparable with those of standard bonds on metal bond-pads. Direct wire-bonding eliminates the metallization step, thus alleviating the constraint of consecutive high-temperature micromachining processes.Copyright

A Novel Tilting Micromirror with a Triangular Waveform Resonance Response and an Adjustable Resonance Frequency for Raster Scanning Applications

We present a novel tilting micro-mirror that has a triangular waveform resonance response, and a resonance frequency that can be continuously and reversibly adjusted. The triangular waveform and the adjustability of the resonance frequency are crucially important for raster-scanning applications. Although the mirror is driven by electrostatic forces, the triangular waveform is achieved by mechanical means. Our micro-mirror is driven by up to 60 Volts whereas to achieve the same waveform without the novel mechanical design would require extremely high voltages.

Direct Wire-Bonding of Silicon Devices Without Metal Pads

We demonstrate a new method for direct wire-bonding of silicon devices, which does not require any metal bond-pads. A wire bond-ball is pressed into a hole etched in the silicon device layer, and is wedged in the hole by plastic deformation. Experimental measurements show that strength and conductivity of direct-bonds are comparable to those of standard wire-bonds on metal pads. The relevance of direct wire-bonding is that by eliminating metal bond-pads, constraints on high temperature processing steps and limitations on sacrificial release steps, are alleviated.

Determining the strength of micro-beams without measuring forces or displacements

It is demonstrated that the strength of brittle micro-beams can be measured without measuring any forces or displacements. A novel test device is presented in which the strength of brittle beams is directly deduced from their size after failure.

Electromechanical sensing of charge retention on floating electrodes

This paper considers the electromechanical response of electrostatic actuators that are driven by both voltage and charge. The model system is an electrostatic actuator in which the suspended electrode is subjected to a driving voltage and the fixed electrode, which is electrostatically floating, is loaded by charge. The response of the system is analyzed using energy methods, and it is shown that the system has two distinct pull-in voltages. It is also shown that the amplitude of charge on the floating electrode is proportional to the average of these two pull-in voltages. Test-actuators were designed, fabricated, and characterized, and their measured response validates the theoretical predictions. A nondisruptive measurement of charge is proposed and demonstrated which enables to monitor charge decay over time.

Measuring the Strength of Brittle Microbeams Without Measuring Forces or Displacements

A new test device for measuring strength of brittle microbeams was recently proposed. This test device requires no measurement of applied forces or of deformation. In this work, the theoretical analysis that explains how the strength of microbeams may be deduced from the length of the remaining ligament of broken beams is presented