Barium Titanate Based Materials for Intelligent Thermoelectric Converters with Dynamic Workload Management

Mobile devices are nowadays an all-pervasive technology. Their number is expected to reach 17.72 billion worldwide by 2024, an increase of 3.7 billion devices compared to 2020 levels¹. A typical cell phone gives off around 0.2 Watts of heat when idle, and closer to a Watt while making a call or running processor-intensive applications. The heat generated by a tablet or laptop is much higher. Almost all this heat is never recovered.<br/>Currently, high and medium-grade heat are the easiest to recover. In contrast, the low-grade heat is usually wasted in the environment, although, it is approximately more than 50% of the entire wasted heat². This is because i) the currently achieved efficiency of the heat to electricity conversion at these temperatures is very low and ii) because, under the condition of constant heat flux generation, it is challenging to maintain a temperature gradient (or heat oscillation) required for the operation of the conventional thermoelectric converters.<br/>In this paper, we will present our latest achievements in developing barium titanate-based materials that could be used to build an intelligent thin film thermoelectric (TFTE) converter attached to a digital system/device with dynamic workload management.<br/>We will review the requirements imposed on the active materials and will compare them with our current results. We will further discuss in detail materials’ structural properties examined using SEM and x-ray diffraction, and their dielectric properties (dielectric permittivity and P-E hysteresis loops) measured in a temperature range between 80-450K at frequencies up to 1MHz.<br/>Due to the small heat mass of our TFTE converter, it is possible to achieve a rapid heating-cooling cycle and therefore to recover substantial wasted heat per unit time.<br/><br/>References:<br/>1. https://www.statista.com/statistics/245501/multiple-mobile-device-ownership-worldwide/.<br/>2. I. Johnson, et al., (2008) Waste Heat Recovery, https://tinyurl.com/wkuvftfr;