This Small Business Innovation Research (SBIR) Phase I project will develop a robust, facile, and economical process to fabricate microscale electrode assemblies for Molecular Electronic Technology (MET) inertial sensors. These devices sensitively detect motion based on an electrochemical sensing mechanism. Currently, platinum or platinum alloys are used as electrode materials. However, the high cost of platinum is a major cost driver for MET sensors. The new electrode assemblies will comprise a composite structure of glassy carbon electrodes and silicon carbide nitride insulating layers to isolate the electrodes within the multi-layer structure. The proposed process utilizes polymer precursors for both these materials which will be cast in successive layers and fired under proper conditions to create the desired structures. In Phase I, an experimental parametric study will be performed to demonstrate feasibility for the process, partnering with Professor Prakash at The Ohio State University. Phase II will be devoted to fabrication, testing and optimization of electrode assemblies and development of plans for large scale production. Successful completion of the program will result in substantial cost savings for existing MET seismic sensor products, and will enable development of new low cost sensors for automotive navigation and other markets.
The broader impact/commercial potential of this project is significant in several aspects. The low-cost electrode assembly to be developed can improve the profitability of MET sensor products across the board. MET Tech's initial product offering is a seismic sensor for oil and gas exploration, with a served available market of $100M/year. The availability of high performance, low cost inertial sensors can also enable new functionality in consumer electronic devices, such as inertial navigation capability in cell phones. Market sectors affected include energy, transportation, civilian and military navigation, and consumer electronics. From a broader technological and scientific perspective, this project will establish the ability to co-fire glassy carbon with an insulating material for the first time, which should enable new classes of composite structures and devices at the micro- and possibly at the nanoscale. Such electrode assemblies could have applications in other systems operating in harsh conditions such as high temperature fuel cells, space applications, corrosive environments in chemical processing, as well as in medical applications since glassy carbon is biocompatible. The program will also foster collaboration between academic and industrial researchers and train students and post-docs in practical applications of microfabrication technology, and create new high-technology jobs.
In this project MET Tech is developing a novel process to fabricate a key part of our inertial sensors – the sensing element – with a lower cost substitute for the costly platinum currently used. MET Tech’s inertial sensors (including accelerometers, rate sensors, gyroscopes, seismic sensors and others) operate by a mechanism unique among commercial inertial technologies, having an electrochemical sensing mechanism. This requires an inert electrode material in the sensing element; current MET sensing elements utilize platinum or platinum alloys, which are a major cost driver for the sensors. Glassy carbon is also a suitable electrode material for MET sensors, and is potentially orders of magnitude less expensive than platinum. In addition to cost savings, glassy carbon electrodes have the potential to be more robust in harsh environments. The project is developing a process to fabricate MET sensing elements, which are a multilayer assembly consisting of glassy carbon electrode layers and silicon carbide nitride dielectric spacer layers, with both materials cast from special resins. The Phase I project successfully accomplished all key steps necessary to fabricate the new parts, and we are confident that a Phase II project will be fully successful in fabricating prototype sensing elements and developing a robust process for their large-scale production. This project establishes the ability to co-fire glassy carbon with an insulating material for the first time, which should enable new classes of composite structures and devices at the micro- and possibly at the nanoscale. Besides dramatically reducing the cost of MET sensors, thus improving market share for our products, such electrode assemblies could have applications in other systems operating in harsh conditions such as high temperature fuel cells, space applications, corrosive environments in chemical processing, as well as in medical applications since glassy carbon is biocompatible.
