Thermal metrology at the nano scale With the evolution of nanotechnology has come the need to develop a whole new set of standards and metrology. Standardised definitions, tools, calibration samples and models for thermal transport in nano-structured materials will foster global progress. Industrial Technologies © Thinkstock Nanomaterials have many amazing and exotic electrical, mechanical, thermal, optical and magnetic properties that differ greatly from those of the same materials in bulk form. The EU-funded project QUANTIHEAT (Quantitative scanning probe microscopy techniques for heat transfer management in nanomaterials and nanodevices) is tackling the job of developing currently non-existent standardised metrological definitions, tools and methods to study and quantify heat transport in nano-structured materials. The team started off with industry-specified sample materials and a cataloguing of the thermal characterisation techniques and methodologies available within the consortium for multiscale analysis of heat transfer. This effort enabled scientists to determine which measurement and modelling techniques would be most appropriate for the given materials. A review of definitions and terminology currently used pointed to the very high potential for confusion in describing the results of scanning thermal microscopy (SThM). It also highlighted the critical need for well-characterised samples allowing interlaboratory comparisons. Recommendations have been made in the form of a preliminary document intended to lead to standardised definitions. A large portion of the work is dedicated to developing new metrology tools including calibration, reference and test samples, as well as models with a focus on industrial fabrication methods. Industrial samples of nanoimprint lithography resist thin films, novel nano-structured microparticle-based interconnects and materials created with atomic layer deposition have been fabricated and evaluated. Results have aided scientists in determining the thermal characterisation techniques required to address critical thermal transfer aspects of the manufacturing processes. Researchers have also made important progress in development of advanced simulation and semi-analytical tools for investigating thermal behaviours in complex materials and at their interfaces. In parallel, researchers have developed new measurement and calibration devices, including experimental probes and combinations of SThM with scanning electron microscopy or infrared radiometry. QUANTIHEAT is well on its way to delivery of a whole new set of metrology tools to investigate heat transport in nano-structured materials. They will be submitted to the European and international standards organisations in order to establish internationally agreed upon calibration standards and models. This invaluable contribution to the critically important field of nanomaterials will also enhance the competitive edge of EU manufacturers. Keywords Thermal, metrology, nano, microscopy, heat transfer
