Public defence in materials science, M.Sc.(Tech.) Mhd Adel Assad

Title of the thesis: Disordered metasurfaces for energy capture, camouflage, and stealth via polarizonic interference

Thesis defender: Mhd Adel Assad
Opponent: Prof. Ing. Andrei Choukourov, Charles University, Czech Republic
Custos: Prof. Mady Elbahri, Aalto University School of Chemical Engineering

In response to the converging global challenges of climate change, energy sustainability, and advanced defense technologies, the development of materials capable of controlling light and heat across multiple spectral domains has become increasingly critical. Modern applications, ranging from energy-efficient building facades and solar harvesting systems to multispectral camouflage and infrared stealth, demand optical coatings that are not only spectrally versatile but also scalable, cost-effective, and mechanically robust. 

This doctoral thesis introduces disordered metasurfaces for achieving multifunctional optical responses governed by energy capture, camouflage, and stealth applications. At the heart of this framework is the newly developed concept of polarizonic interference, which is an emergent light-matter interaction that enables broadband, omnidirectional, and angle-insensitive optical responses without reliance on periodicity or lithographic precision. 

The research progresses through three key demonstrations. First, the introduction of polarizonic interference and the development of vividly colored polarizonic foils that provide pigment-free structural color combined with spectrally selective solar absorption; Second, the realization of multiband stealth coatings capable of simultaneous ultraviolet absorption, visible-range camouflage, and infrared suppression within a single ultrathin layer; and third, the design of cloud-inspired metasurfaces that regulate thermal management through engineered backscattering and heat-trapping. 

These disordered metasurfaces are fabricated entirely through a scalable physical vapor deposition method, eliminating the need for cleanroom facilities and complex patterning. Collectively, this thesis establishes a new paradigm in optical materials design by demonstrating how disordered metasurfaces can deliver scalable, multifunctional, and environmentally sustainable solutions for energy harvesting, spectral camouflage, and thermal management.

Keywords: Disordered, Metasurfaces, Polarizonic Interference, Absorbers, Camouflage, Stealth

Thesis available for public display 7 days prior to the defence at Aaltodoc. 

Contact information: 

Adel Assad 
+358449400046
Adel.Assad@aalto.fi 
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