MERGING

Membrane-based phononic engineering for energy harvesting

 Partecipanti

Mappa

 Word cloud

Esplora la "nuvola delle parole (Word Cloud) per avere un'idea di massima del progetto.

 Obiettivo del progetto (Objective)

'The aim of this proposal is to realise a compact thermoelectric module to harvest the energy of devices to be used in applications requiring heterogeneous integration packaging techniques leading to small size, integrability and high thermoelectric efficiency. Our concept, which goes up to a test device, is based on deep understanding of the behaviour of phonons, their control leading to the control of thermal transport. It is based on minimizing the thermal conductance and or thermal conductivity by phonon engineering. A ZT=2.5 is targeted together with module compactness and integration potential. The module will be based on technologies combining Si microelectronics, thin film thermoelectric material and novel concepts to understand heat transport in 2-dimensional (2D) nanostructured materials such as Si-based ultrathin membranes, GeMn and strontium titanate. The device will carry enough current but insignificant or little heat. Theoretical and experimental investigations of heat transport will be carried out. The methods and technologies developed will enable nm-scale control of energy generation and heat flow. This will impact on on-chip and in-package energy management that is of crucial importance for future technologies. Especially, our targets contribute to (a) on-chip harvesting of thermoelectricity and (b) management of heat flow in the applications of heterogeneous integration and nanoelectronics.'

Introduzione (Teaser)

The trend in microelectronics to put more computational power in smaller packages pushes the threshold of heat management capabilities. Scientists are developing novel thermoelectric modules to harvest waste heat and use it to support chip functions.

Descrizione progetto (Article)

So many transistors in such a small space dissipate too much heat, impeding chip function. This makes it increasingly important to find ways to control heat flow, particularly through crystalline materials, such as silicon, that form the foundation of most devices.

Thermal or vibrational energy from atoms oscillating in a crystal lattice is embodied in phonons, the particle equivalent of the mechanical wave that is created. Controlling phonons thus enables control of thermal transport, and this is the topic of the EU-funded project 'Membrane-based phononic engineering for energy harvesting' (http://www.merging.eu/ (MERGING)).

Scientists are developing a thermoelectric generator (TEG) module to convert waste heat to electricity, offsetting the power requirements of increasingly power-hungry microelectronics while minimising heat build-up. The TEG will be used in on-chip harvesting of thermoelectricity in concentrating photovoltaic systems. It will also support one of the most important emerging design concepts: heterogeneous integration or joining of diverse materials and devices on a common substrate platform. This will be done in the context of thermoelectric cooling of a complementary metal-oxide-semiconductor high-resolution camera. MERGING is thus focusing on silicon-compatible materials and technologies.

The team has developed and applied advanced techniques to measure thermal properties in membranes and thin films. Experimental work is complemented by extensive theoretical investigation of thermal energy transport. The team has revealed the underlying cause of nearly 30-fold reductions in thermal conductivity of ultra-thin silicon membranes observed experimentally. They have also produced germanium-based nano-structured materials with 50 times lower conductivity than bulk material.

A new neural network model reproduces the vibrational properties of nano-structured germanium manganese and will support development work. Finally, the team has fabricated silicon and germanium membranes with phononic crystals and demonstrated the effect of those crystals on phonon dispersion and the thermal properties of the membranes.

MERGING outcomes for turning otherwise wasted heat to good use will have important impact on information and communications technologies and energy, vitally important market sectors. Optimisation of the lab-scale technology using autonomous and embedded sensors could eventually improve the situation for other sectors such as health and the environment as well.