MechE Colloquium: Leveraging the physics of sunlight-surface interactions to derive photothermal materials controlling atmospheric vapor condensation


Event details

Date 22.11.2022
Hour 12:0013:00
Speaker Prof. Dimos Poulikakos, Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich
Location Online
Category Conferences - Seminars
Event Language English
Abstract: Interfaces separating different kinds of matter, or different phases of the same matter, abandon in nature and technology. What is more, they invariably play a critical role in all systems where they occur, from regulating transport of energy and species, to dictating system shape and form. Interfaces differ in their structure and properties from the bulk matter they surround and can be engineered to effect remarkable outcomes in a broad palette of applications. In this lecture, I will primarily focus on liquid/gas and liquid/solid interfaces, and their interaction with sunlight, employed in the rational design of photothermal devices and metasurfaces, to control atmospheric water condensation, according to our will. On the one hand, I will discuss energy neutral devices yielding maximum water harvesting from atmospheric air. Their function is based on radiative cooling to the outer space with optimized solar radiation shielding, coupled with a fully passive superhydrophobic condensate harvester, and yields uninterrupted atmospheric water harvesting, not only during night-time but also during daytime. On the other hand, when condensation is undesirable, I will demonstrate materials (photothermal metasurface coatings) that prohibit condensation “fogging” from forming on transparent surfaces, functioning with selective sunlight absorption, which enables them to maintain surface transparency to visible light. These photothermal coatings are unprecedented in their thinness (less than 10 nm) and performance, can be easily deposited also on deformable and soft materials, and are fabricated with common industrial processes. These combined capabilities render them a perfect candidate for a host of applications such as eyewear, car windows and windshields, mirrors and building windows.

Biography: Professor Dimos Poulikakos holds the Chair of Thermodynamics at ETH Zurich, where in 1996 he founded the Laboratory of Thermodynamics in Emerging Technologies. He served as the Vice President of Research of ETH Zurich in the period 2005-2007. Professor Poulikakos was the ETH director of the IBM-ETH Binnig-Rohrer Nanotechnology center, a unique private-public partnership in nanotechnology at the interface of basic research and future oriented applications (2008-2011). He served as the Head of the Mechanical and Process Engineering Department at ETH Zurich (2011-2014). He was the Chairperson of the Energy Science Center of ETH Zurich (2018-2021) and is currently a member of CORE, the advisory board of the Swiss government on issues related to energy. As of January 2020, he is also the president of Division IV of the Swiss National Science Foundation (SNF) and member of the presiding board of SNF. His research is in the area of interfacial transport phenomena, thermodynamics and related materials nanoengineering, with a host of related applications. The focus is on understanding the related physics, in particular at the micro- and nanoscales and employing this knowledge to the development of novel technologies. Specific current examples of application areas are the direct printing of complex liquids and colloids with nanoscale feature size and resolution, the science-based design of supericephobic and omniphobic surfaces, the chip/transistor-level, bio-inspired 3D integrated cooling and energy optimization of supercomputer electronics, the development of facile methods based on plasmonics for sunlight management in energy applications and the development of nanofluidic technologies and surface textures for biological applications under realistic fluidic environments (accelerated and guided cell adhesion, re-endothelialization, antifibrotic surface textures and materials, single virus trapping and transport).

Practical information

  • General public
  • Free



MechE Colloquium: Leveraging the physics of sunlight-surface interactions to derive photothermal materials controlling atmospheric vapor condensation