Noel C. MacDonald

Learn More
Programmable vector elds can be used to control a variety of exible planar parts feeders. These devices can exploit exotic actuation technologies such as arrayed, massively-parallel microfabricated motion pixels or transversely vibrating (macroscopic) plates. These new automation designs promise great exibility, speed, and dexterity|we believe they may be(More)
This paper investigates manipulation tasks with arrays of microelectromechanical structures (MEMS). We develop a geometric model for the mechanics of microactuators and a theory of sensorless, parallel manipulation, and we describe e cient algorithms for their evaluation. The theory of limit surfaces o ers a purely geometric characterization of microscale(More)
Previous in vitro studies have demonstrated increased vascular endothelial cell adhesion on random nanostructured titanium (Ti) surfaces compared with conventional (or nanometer smooth) Ti surfaces. These results indicated for the first time the potential nanophase metals have for improving vascular stent efficacy. However, considering the structural(More)
Programmable vector elds can be used to control a variety of exible planar parts feeders. These devices can exploit exotic actuation technologies such as arrayed, massively-parallel micro-fabricated motion pixels or transversely vibrating (macroscopic) plates. These new automation designs promise great exibility, speed, and dexterity|we believe they may be(More)
Arrays of electrostatic MEMS actuators have been fabricated using a modi ed, multi-layer SCREAM (SingleCrystal Reactive Etching and Metallization) process. The devices consist of released, torsionally suspended grids with high aspect ratio single-crystal silicon (SCS) tips. They can be used to generate a force eld for the manipulation of small, at objects.(More)
Programmable force vector fields can be used to control a variety of flexible planar parts feeders such as massively parallel microactuator arrays or transversely vibrating (macroscopic) plates. These new automation designs promise great flexibility, speed, and dexterity— we believe they may be employed to position, orient, singulate, sort, feed, and(More)
Programmable vector elds can be used to control a variety of exible planar parts feeders. These devices can exploit exotic actuation technologies such as arrayed, massively-parallel microfabricated motion pixels or transversely vibrating (macroscopic) plates. These new automation designs promise great exibility, speed, and dexterity|we believe they may be(More)
A single-mask lateral tunneling accelerometer with integrated tip has been developed and characterized. High aspect ratio single-crystal silicon springs provide high resolution, wide operating bandwidth, and excellent isolation from off-axis stimuli. In this paper, we present the first such device implementing the SCREAM [1] process technology. We focus on(More)
Recent process developments have permitted the highly anisotropic bulk micromachining of titanium microelectromechanical systems (MEMS). By using the metal anisotropic reactive ion etching with oxidation (MARIO) process, arbitrarily high-aspect-ratio structures with straight sidewalls and micrometre-scale features have been bulk micromachined into titanium(More)