(5d) A Chemistry Teaching Module From a MEMS Project

In this applied project, which originated from MIT research, a Micro-Electro-Mechanical Systems or MEMS device was designed to detect NOx emissions in vehicles.  This micro-fabricated device is a micro-sensor which converts a measured mechanical signal into an electrical signal to detect this greenhouse gas.  In Phase I of the project the initial design and function parameters of the MEMS device were determined and a preliminary prototype was developed.  Determination of the generator resonator die, the NOx sensitive coatings, packaging solutions and the electronics was done in Phase I.  Improving the design and fabrication of the micro-sensor array, developing packaging for operation of the sensor at temperatures above 800ºC and compaction of the sensor components to enable sub-second reaction time are critical components of the current Phase II.  The chemical component of this fast response, high sensitivity, MEMS based NOx sensor is the coating/sensing material adsorbed onto the resonator.  In order to increase selectivity to NOx emissions and temperature sensitivity, there has to be optimal integration of a functional coating on the micro-resonator.  Two specific perovskite and one zeolite compound were selected.  These coatings were selected due to their ability to catalyze a NO oxidation process as well as for their absorption properties relative to the inorganic matrix of the absorbent.  The catalysis and absorption properties of the selected coatings are temperature dependent. 

This complex and multi-disciplinary entrepreneurial and research project provides rich and relevant material for a case study in chemistry careers, principles and practice.  An extension of the “instructor-as-researcher” component of an NSF grant is the development of a set of learning modules designed for high school chemistry.  These work sets mimic the research to production questions present in this and many projects.  The modules include a novel “chemstory” assessment and a literature search-to-experimental design project-which incorporates critical thinking and writing.  It also has a career study which outlines the eight science/engineering disciplines drawn upon for this business endeavor.  Other, more standard course segments incorporate the laboratory procedures, data collection and key science concepts involved in this work.  There is a value added section as well for the most advanced, possibly AP students.  This is an innovative bench-to-pilot to production scale curriculum project.  Problem solving, process design, scale-up and instrumentation are incorporated. The chemistry/pre-(chemical) engineering, mathematics, writing, economics and autoCAD components are keyed and identified on a concept map.  This can be taught as a complete unit, used as an extracurricular chemical project, or components can be used to augment a math, chemistry or related class.  The design and use of this curriculum for outreach will be featured. 

This is an example of outreach to instructors, teachers and the recipients, students.  When this material is taught in schools through a chemistry club or in conjunction with NOBCChe as an extracurricular mentor project, it reaches students who might not otherwise be exposed to chemistry or chemical engineering in a meaningful way.  NSF is providing outreach by even funding this type of project which provides innovative research opportunities for teachers and instructors who may not otherwise gain experience in industry.