Dip pen nanolithography (DPN) is a method of creating nanoscale chemical patterns on surfaces using an atomic force microscope (AFM) probe. Until now, efforts to increase the process throughput have focused on passive multi-probe arrays and active arrays based on thermal bimetallic actuation. This paper describes the first use of electrostatic actuation to create an active DPN probe array. Elec...

The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the elect...

This paper introduces a novel design for a hybrid micromachined contactless suspension, whose operation is based on combining electromagnetic inductive and electrostatic actuation. Wirebonded microcoils provide the electromagnetic inductive actuation, while electrodes patterned on a Si wafer provide electrostatic control. The coil structure and the electrode structure are independently designed...

Microvalves are critical in the operation of integrated microfluidic chips for a wide range of applications. In this paper, we present an analytical model to guide the design of electrostatic microvalves that can be integrated into microfluidic chips using standard fabrication processes and can reliably operate at low actuation potentials (<250 V). Based on the analytical model, we identify des...

In this paper, the stability of a functionally graded magneto-electro-elastic (FG-MEE) micro-beam under actuation of electrostatic pressure is studied. For this purpose Euler-Bernoulli beam theory and constitutive relations for magneto-electro-elastic (MEE) materials have been used. We have supposed that material properties vary exponentially along the thickness direction of the micro-beam. Gov...

In this paper, the snap-through buckling of an initially curved microbeam subject to an electrostatic force, accounting for fringing field effect, is investigated. The general governing equations of the curved microbeam are developed using Euler-Bernoulli beam theory and used to develop a new criterion for the snap-through buckling of that beam. The size effect of the microbeam is accounted for...

A model for a chaotic micro-oscillator is developed by adding a new control system to an electrostatic actuator consisting of two electrodes: the substrate and a cantilever beam on top. The electrostatic actuator itself has a single stable equilibrium over a range of voltage, whereas adding the controller, which has a quadratic function, creates a voltage range for bistability. The bi-stability...

Actuation devices are used for many space applications and there is increasing need to reduce their size, mass, cost and power consumption. To address this need, JPL is developing electroactive polymers (EAP) with emphasis on two EAP categories that induce large bending and longitudinal actuation strains. Comparison between EAP and the widely used transducing actuators shows that, while lagging...

This paper proposes a ramp dual-pulse actuation-voltage waveform that reduces actuation-voltage shift in capacitive microelectromechanical system (MEMS) switches. The proposed waveform as well as two reported waveforms (dual pulse, and novel dual-pulse) are analyzed using equivalent-circuit and equation models. Based on the analysis outcome, the paper provides a clear understanding of trapped c...

There have been growing interests in direct patterning of metallic contents on the surface of the substrate without including complex steps of the micro fabrication lithography process. The direct fabrication process using ink-jet printing can be expected to be a powerful tool for both nanotechnology research and applications such as micro electronics. Inkjet printers operate by propelling vari...