Cement-based electronics

Abstract

The term Intelligent Highway is usually intended to mean external systems that are added to pre-existing highways. However, the ability to construct basic passive electronic elements is demonstrated employing electrically dissimilar Portland cement pastes. These electronic elements include resistors, rectifying pn-junctions, piezoelectric and piezoresistive sensors, and thermocouple junctions. It may therefore be possible to build intelligence into the highway itself utilizing cement-based electronic devices. As compared to semiconductor-based electronic components, those derived from cement have minimal materials and processing costs, do not require clean rooms, and are mechanically more rugged. Results and characterizations are presented for resistive elements and rectifying pn-junctions derived from admixtures of stainless steel fiber (n-type) and carbon fiber (p-type) in Portland cement. These elements are then combined to produce a monolithic cement-based digital logic 2-input AND gate.