Ever since freshwater scarcity has become a threat to the sustainable development of human society, increasing access to freshwater is very important to our society. In this environment, utilizing saline waters from the oceans and other sources is attracting more and more attention. Due to the clean and sustainable characteristics of solar energy, solar-driven evaporation is becoming one of the promising approaches for water desalination and purification. 

The traditional solar-driven evaporation system has many disadvantages such as low efficiency and high cost because bulk water needs to be heated to a high temperature to generate water vapor, resulting in a slow response to sunlight and heat loss to the bulk water or the external environment. The interfacial solar-driven evaporation approach emerges as the times require. Compared with the bulk water-heating method, the interfacial solar-driven evaporation approach mainly localizes the heat generation at the water-air interface to avoid heating a large volume of water, e.g., the ocean, which serves as a low-temperature sink. 

Even with intensive efforts so far, almost all studies have focused on multi-layered structures that make the solar-driven evaporation process more complex, more expensive, and more difficult for mass production.

Technology Overview

Northeastern University researchers propose an all-in-one high-effective evaporator for solar-driven steam generation and water desalination. This evaporator is a microscale porous structure made of copper (Cu) with nanoscale copper oxides (CuO and Cu2O) grown over its entire surface. It is a novel porous structure for the first time designing and demonstrating for solar-water treatment purposes. Unlike the state-of-the-art technique using an interfacial structure consisting of multi-layers, each layer serving as a solar absorber, water pathway, and a thermal barrier respectively, the invented all-in-one structure comes with only a single layer of Cu porous structure (form) with multi-functionalities. 

Under solar irradiation, the invented structure has been experimentally demonstrated to achieve the highest evaporation rate at 2.8 L/m2 h for room temperature water (25 degrees C) and a breakthrough rate at 5.4 L/m2 h at preheated water of 80 degrees C if integrated with the Soleeva solar energy technique. 


  • Effectively solve the global freshwater crisis through the exploration of usage of solar thermal evaporation processes 
  • An all-in-one design, simple, low cost, lightweight, and ease for manufacturing, unlike the state-of-the-art multi-layered interfacial structure 
  • A 3D array of the invented tilted porous structures can be aligned for installation, with a better angle facing the sun (high incident angle of sunlight) and less projected areas over water for a higher efficiency 
  • Two stable types of copper oxides (CuO and Cu2O) both are ideal anti-fouling and anti-biofilm materials, potentially address the algae and other water contaminant problems 
  • This invention enables freshwater recovery from not only saltwater but also brackish, polluted, and contaminated water sources


  • High-rate pure steam generation 
  • Water desalination and purification 
  • An integrated solar photovoltaic energy and water system 
  • Light-weight, portable, adaptable to any field conditions (disaster areas and commercial, logistics, potential military usages)


  • License
  • Partnering
  • Research collaboration
Patent Information:
For Information, Contact:
Mark Saulich
Associate Director of Commercialization
Northeastern University
Yi Zheng
Ralph Ahlgren
Mohamed Sonbaty
all in one
drinkable water
high-rate evaporation
potable water
solar driven device
water desalination and purification