Abstract
Electrical conductivity is a basic property of materials that determines how well the material conducts electricity. However, models are needed that help explain how conductors function as their size and temperature changes. This research demonstrates and explains how important atomic motion is in understanding electrical conductivity for conductors (and thus the ability of metals to function as temperature sensors). A derivation is performed (on an atomic level) that provides a theoretical relationship between electrical resistivity, temperature, and material thickness. Subsequently, computational models are used to determine the optimal parameters for the theoretical models as well as the conditions under which they are accurate. Comparisons are performed using experimental data showing that the models are valid and accurate.
TopIntroduction
Resistance temperature detectors (RTDs) are metals that function as temperature sensors. These devices have a well known response between their electrical resistance and temperature. As a result, these materials have found much success as temperature detectors or temperature sensors. Because temperature measurements are necessary in many diverse fields, RTDs currently find applications in biology and medicine (Cavallini 2012, Liu 2014, Yi 2014), battery and fuel cell research (Lee 2013, Lee 2014, Wang 2014a), aeronautics (Daniels 2012, Miyakawa 2012). materials science (Abeykoon 2012, Zhang 2013, Jiang 2014), environmental monitoring (Park 2011, Li 2012, Holstein-Rathlou 2014), food processing (Singh 2012, Ranasinghe 2013), and chemical or gas detection (Chee 2014, Wang 2014b). Reducing the size of RTDs for these applications could affect their response.
Key Terms in this Chapter
Resistance: A property that is based on a material’s resistivity and dimensions and determines how well the material will prevent the flow of electric current.
Conductivity: A fundamental property that determines how well a material allows the flow of electric current.
Resistivity: A fundamental property that determines how well a material prevents the flow of electric current.
Finite Element Modeling: A computational technique used to find solutions to complex mathematical equations.
Nanoscale: A reference to a material with one dimension of at most 100 nanometers.
Mean Free Path: The average distance an electron travels in a material before it collides with an atom.
Thin Film: A material that has an approximate thickness of no greater than several micrometers.
Crystal Lattice: This represents the periodic arrangement of atoms in a material.
Resistance Temperature Detector: A sensor or device that measures temperature through the material’s change in electrical resistance.