Introducing "lab-on-a-chip" type experimental activities in "Thermodynamics and Heat Transfer Laboratory" course

Abstract

In recent years, increasing industry demands for skilled graduates from universities has required a substantial refocus on engineering technology programs across the nation towards improving or even changing their traditional ways of imparting knowledge to students. One aim is to incorporate as much hands-on activities as possible in their curricula without having to curtail the theoretical foundation and yet to stay within the total number of existing credit hours. However, adding more laboratory activities implies a financial burden on the department and institution. In particular, for thermal-fluid educational areas, experimental equipment could be excessively costly, requiring dedicated laboratory space. Our thermal-fluid courses included up to now only laboratory activities based on traditional 'bench-scale' equipment. While these experiments have proven to be valuable educational tools for our courses, we continue to strive to improve and adapt our curricula to include more current and innovative experiments. To overcome both financial and space constraints that presently limit the laboratory, we developed sustainable improvements of "Thermodynamics and Heat Transfer Lab" course, including several "lab-on-achip" based activities to support our educational objectives in thermal sciences and process engineering. Micro-fluidics (Lab-on-a-chip) approach has tremendous potential in scientific and emerging industrial applications from health care (clinical diagnostics) and medical research to microelectromechanical systems and sensors. As a result of these experimental activities, students will gain both in-depth understanding of physical phenomena presented in the lectures and hands-on experience in developing and working with these miniaturized devices and systems1-7. In this paper we report the development of laboratory activities introduced in the revised "Thermo and Heat Transfer Lab" course that has been offered during the winter term of AY2011-2012. The impact of the new activities has been assessed during this term and will continue to be evaluated and improved during subsequent terms when the course will be offered. Because this is mainly a junior to senior undergraduate course, this assessment will also focus on evaluating the level of critical thinking and creativity development that the course is promoting17. The activities are based on development of microfluidic devices that will allow students to visualize streams and types of flows and also evaluate enthalpy of formation of a substance, and heat capacity of substances, heat production. The temperature variation is controlled by microheaters and local micro-temperature and pressure sensors embedded around the channels formed in plastic substrate 'chips'. The micro-calorimeter device type is expected to give an excellent control of the thermal transfer, phenomenon that can be explored further by students extending the experiments into small team projects8-12. The fabrication of these micro-devices is fairly inexpensive and can be produced in our lab facility. © 2012 American Society for Engineering Education.