Design of a vibration isolation system

Vibration isolation is very important for advanced production and high-resolution measurements; these include semiconductor chip manufacturing, scanning probe microscopy, holographic interferometer, co focal optical imaging, etc.

Conventionally, an arrangement of springs and dampers is used as isolator and the objective is selection of spring and damper parameters to optimally reduce

(i)  Vibrations transmitted from ground through the suspension and

(ii) Vibrations caused by disturbances acting on an isolation table directly. A suspension with less stiffness is better for reducing the former because dynamic coupling between the vibration source and the isolation table is weakened; thus, zero stiffness is ideal in this case. However, higher stiffness is better for suppressing the latter because it reduces displacement of the isolation table from its desired position; thus, infinite stiffness is ideal in this case. In conventional spring-damper arrangement, the two conflicting requirements cannot be simultaneously achieved. However, recently, a novel approach has been presented to achieve both the requirements by incorporating the concept of negative stiffness.

This project will aim at designing a vibration isolation system utilizing the concept of negative stiffness. Mechanical hardware will be fabricated, necessary sensors and electronics will be implemented. A control algorithm will be implemented.