Objectives

Main objectives & Impact

The MIRACLE project opens a radically unexplored scientific and engineering avenue, i.e. the concept of Photonic Meta-Concretes (PMC), and endeavours to

1 prove the feasibility of this idea by developing for the first time in the state of the art a radiative cooling device based on a PMC
2 fabricate a prototype whose radiative cooling performance will be validated on the roof of a real building and
3 start the roadmap of this emerging S&T avenue (PMC) by evaluating its potential environmental impact and exploring how the PMCs could be used in other applications.

RADIATIVE COOLING TECHNOLOGY

  • All bodies in the Earth are in continuous exchange of energy with the sun and the atmosphere, with a net balance of power that depends on the incoming solar (short wave) and atmospheric radiation, the emitted thermal radiation and non-radiative heat exchanges.
  • Unfortunately the atmosphere works like an opaque shield in most of the thermal radiation wavelengths (greenhouse effect!).
  • Radiative cooling technology utilizes the atmospheric transparency window (8-13 mm), called Atmospheric Window (AW), to passively dissipate heat from the Earth to outer space.

RADIATIVE COOLING TECHNOLOGY

In the theory, easy…
“Easy” recipe for daytime applications….

  • Maximize the solar reflectance
  • Maximize the emissivity in the AW
  • Minimize the non-radiative loss

In practice, quite complex

  • Technologically unfeasible until the advent of photonic meta-materials.
  • 1st proof of concept in 2014!
  • Current solutions are based on either Meta-materials or on Hierarchical porous materials.

INTRINSICALLY HIERARCHICAL POROUS STRUCTURE


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OFTEN REINFORCED BY MICROFIBRES

PHOTONIC META-CONCRETE

Based on an ordered arrangement of the steel microfibres that work in combination with the hierarchical porous structure of concrete.Based on an ordered arrangement of the steel microfibres that work in combination with the hierarchical porous structure of concrete.

  • Cheap & scalable, and not “convection shields”
  • Large impact
  • Sound from a materials point of view
  • Tunable composition
  • Tunable porosity

 

Implementation by

  • advanced optimization methods based on deep learning technologies at the design level
  • inverse-phase fabrication methodology  (micro-patterned concrete moulds will be produced by two-photon polymerization technology (2PP)