Brian J. Maclean

MEMS-Based Control of Structural Dynamic Instability

This paper describes the design, analysis and characterization of a prototype active column that applies distributed MEMS technology to the active stabilization of a buckling compressive member. The axial load bearing capacity of structural members can be increased by actively controlling the dynamic instability of buckling. Effective active stabilization is dependent on three primary factors: sensor precision, actuator authority, and control system bandwidth. A networked array of MEMS sensors, filamentary PZT actuators, and recently developed optimal control strategies are combined to demonstrate active control of an inherently unstable column. The active system, designed and simulated using finite element and optimization methods, stabilizes an experimental column for compressive axial loads up to 2.9 times the critical buckling load. Additionally, the system is stable for all loads in the range from tension to this maximum compressive axial load.

Multiregime MEMS sensor networks for smart structures

This paper discusses sensor IC design and packaging approaches, sensor networks architecture and communication protocols, as well as current and future applications of a series of transducers which we have developed in order to address several of the unmet needs of sensing and closed loop control of smart structures and organism-like machines of the future. In particular, the approach described therein has been used to design and manufacture sensors tailored for the measurement of strain, rotation, displacement, pressure, vibration, flow, multi-axis fluid shear, multi-axis strain, tough, multi-axis acceleration, and sound. This paper describes a suite of networkable sensors designed to monitor the internal state of the system, such as strain and joint angle, as well as that of the environment and contact interface with the system, such as pressure, shear stress and contact forces and moments.