Kraft M. – TechConnect Briefs

Design Optimisation of an Electrostatic MEMS Actuator with Low Spring Constant for an “Atom Chip”

Rouabah H.A., Gollasch C.O., Kraft M., University of Southampton, UK

The advance of MEMS based sensors and microfabrication techniques has facilitated innovative technologies such as so-called ‘atom chips’, where a cloud of ultra cold atoms in a Bose Einstein Condensate (BEC) is controlled and manipulated [...]

Higher Order Sigma-Delta Modulator Interfaces for MEMS Capacitive Sensors

Kraft M., Dong Y., Southampton University, UK

Using higher order sigma-delta modulator topologies, similar to the ones used for electronic A/D converters, and applying them to micromachined capacitive sensors is a promising approach to increase the performance of these sesnors. The paper [...]

Design, Modelling and Simulation of a PZN-PT Actuated Micropump

Malleo D., Haas C., Kraft M., University of Southampton, Microelectronics Group, UK

We present an optimization methodology for the design of a self-priming piezoelectrically actuated pump made of a borosilicate glass bonded to silicon. New findings in the design optimization of the piezo-actuated membrane are presented: it [...]

Simulation of Micromachined Inertial Sensors with Higher-Order Single Loop Sigma-Delta Modulators

Dong Y., Kraft M., University of Southampton, UK

Micromachined capacitive inertial sensors incorporated in sigma-delta force-feedback loops have been proven to improve linearity, dynamic range and bandwidth, and also provide a direct digital output. Previous work mainly focused on using only the sensing [...]

Design & Simulation of a Mechanical Amplifier for Inertial Sensing Applications

Kham M.N., Houlihan R., Kraft M., Southampton University, UK

This paper describes the design and simulation of a mechanical amplifier used to improve the performance of a capacitive accelerometer. It comprises a long silicon beam attached to the proof mass and it amplifies the [...]

Noise Considerations for Closed Loop Digital Accelerometers

Gaura E., Kraft M., Coventry University, UK

This paper investigates the noise shaping properties of a sigma-delta modulator type control system applied to a micromachined accelerometer. Three noise sources are present in such an electromechanical closed loop system: mechanical noise due to [...]

Closed Loop Micromachined Inertial Sensors with Higher Order SD-Modulators

Kraft M., Redman-White W., Mokhtari M.E., University of Southampton, UK

Micromachined inertial sensors are often incorporated in closed loop force feedback structures; a particularly advantageous approach is based upon the inclusion of the sensing element in a sigma-delta modulator (SDM) type control structure. The order [...]

Comparison of Two Novel Control Strategies for a Closed Loop Micromachined Tunnelling Accelerometer

Gaura E., Kraft M., Coventry University, UK

This paper presents system level modelling and simulations results of two closed loop, force-feedback control strategies for micromachined tunnelling accelerometers. The first approach is based on the incorporation of the sensing element in a sigma-delta [...]

System Level Simulation of an Electrostatically Levitated Disk

Kraft M., Evans A., University of Southampton, UK

This paper describes the derivation of a system-level model for a micromachined disk which is levitated by electrostatic forces. Such a system has many potential applications for inertial sensors, micro-motors, microfluidic and micro-optical devices. As [...]

System Level Simulation of a Digital Accelerometer

Kraft M., Lewis C.P., Coventry University, UK

This paper describes the derivation of a detailed model of a micromachined accelerometer and its implementation in a commercial SPICE package. The sensing element is modeled at a system level, the control and interface electronics [...]