A Passive High-Temperature High-Pressure Solar Steam Generator for Medical Sterilization

Healthcare-associated infections cause a massive burden for the health care system and the patients. Although the standard sterilization protocol with saturated steam (>121°C and >205 kPa) is effective, generating high-temperature and high-pressure steam is challenging without reliable access to electricity or fuel. While abundant solar energy is readily available, utilizing sunlight to generate steam beyond 100°C requires costly and bulky optomechanical components. In this work, we developed a stationary solar thermal device capable of providing the required saturated steam. Enabled by an optimized transparent aerogel layer, the device can efficiently convert solar energy into heat to drive the steam generation process. Successful sterilization cycles were demonstrated in a field test conducted in Mumbai, India. As a general approach, this work also promises further development of solar thermal technology in energy conversion, storage, and transport applications.