Research

We are currently interested in studying the interplay of thermal, mechanical, optical, and electronic phenomena in novel custom-made micro and nano systems that will fulfill the following goals:

On-Chip Heat-to-Electricity Conversion

Abstract Figure
Figure 1 (a) Schematic of a near-field thermophotovoltaic energy converter. Energy is radiated from a waste heat source towards a low bandgap photovoltaic cell where it is converted to electricity. (b) Spectrum of thermal radiation between the heat source and the photovoltaic cell. At sub-100 nm distance, thermal radiation greatly overcomes the conventional blackbody radiation limit. By properly engineering the emitter material, this radiation spectrum is concentrated at frequencies greater than the PV cell bandgap, thus allowing high efficiency heat-to-electricity conversion.

More than 50% of the energy consumed in industrialized is lost as waste heat and only a negligible (< 0.2%) fraction of this heat is converted back to electrical power. A portable heat-to-electricity conversion module that could be mounted directly on any hot surface would be an ideal solution for recycling this heat into electricity. Unfortunately, whereas large scale heat-to-electricity conversion technologies are mature, low cost and widely used (e.g., boiler, turbines), their smaller solid-state counterparts (e.g., thermoelectric generators) suffer from high cost and low efficiencies.

This project’s goal is to address the lack of efficient portable energy heat-to-electricity conversion technologies using a novel promising approach based the Near-Field Thermophotovoltaics (NFTPV) effect. The principle of this technology is to convert thermal light emitted by a heat source into electrical power using a specially tailored, low bandgap photovoltaic cell. For this process to reach appreciable performances, the distance between the hot side and the photovoltaic cell must be reduced to the sub-100 nm scale, such that the thermal radiation intensity is enhanced by near-field effects (see Figure 1). In this regime, heat could theoretically be converted to electrical power with much greater performance than using current thermoelectric generators.

Nanostructure displacement
Figure 2: Video demonstrating sub-100 distance control between parallel surfaces for near-field radiative heat transfer experiments. The whole frame is less than 0.05 mm wide. More info in our 
Nature Nanotechnology 2016 article

Despite promising performances, there is still no experimental demonstration of NFTPV due to an important technical roadblock: the requirement of bringing parallel objects at sub-100 nm distances, while maintaining a large thermal gradient between them and avoiding contact.

This challenge was only recently overcome using a novel approach developed Prof. St-Gelais’ postdoctoral work at Cornell (see Figure 2). Our goal is now to integrate this distance control technology with an actual photovoltaic cell to implement the first demonstration of this exciting new technology.

 

Radiation Detection

In construction

Vibration Sensing

In construction

Thermal Emission Control

In construction

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