Development of a hydraulically actuated microvalve for space exploration

The advent of spacecraft and rocket technology has expanded space exploration capabilities, further enabling the search for life in outer space. In recent years, research into bioanalytical tools using microfluidic technology has gained popularity with the aerospace industry for the autonomous operation and small footprint. For space explorers, the ability to run quantitative, compositional, and chiral analysis of small organic molecules in situ provides a tremendous advantage over existing methods by minimizing the expense and burdensome equipment previously needed for studying planetary formation, evolution, and decay while looking for signatures of past or present life. Most microfluidic analysis systems utilize pneumatic microvalves and pumps to manipulate target samples for molecular detection and provide high sensitivity and selectivity for detecting various organic compounds. Pneumatically actuated microvalves have been employed extensively in terrestrial applications with a high degree of success. However, applications of the pneumatic microvalve are limited due to the effects of temperature and pressure on the density of the compressible fluid (typically air) used for control of these systems. As a proposed solution to minimize the effect of atmospheric conditions, the development of a hydraulically actuated microvalve has been shown to be a viable alternative to pneumatic actuation. Advantages of hydrodynamic motion generated by piezo linear actuators include significant improvements in both control resolution and adjustable stroke length as compared to the discrete, unidirectional control required for on/off states of current pneumatic systems. The most significant advantage of the hydrodynamic system coupled with the microvalve is the expanded industry application of this technology to include deep ocean and future space exploration missions. Conceptual, experimental and numerical results relating to the proposed hydraulically actuated microvalve are discussed in this thesis presentation.