The 2024 Nils Asplund FAST Prize has been awarded to graduate student Seneca Velling, George Rossman (professor of Mineralogy), and Alex Wertheim for their proposed project on "Additive Manufacturing, Thin-Film Characterization, and Microscopy of Hydrothermal Chimneys". The project will begin January 2024 and complete in 2025. By utilizing resources in the Kavli Nanoscience Institute Laboratory, their effort strives to elucidate the understanding of the life-generating conditions on Earth and other planets, while also building a strong foundation for the 3D printing capabilities in the KNI's nanofabrication cleanroom.
Background: Hydrothermal systems play a critical role in understanding the origins of life on Earth and potentially on other planets, as they may have provided conditions for the first biochemical reactions. These systems are filled with a mixture of minerals and compounds that could have driven the chemical processes needed to turn carbon dioxide into organic molecules, offering insights into the transition from geochemistry to biochemistry.
Laboratory experiments have recreated these hydrothermal conditions, generating intricate structures similar to ones found in nature. These natural structures arise from the interplay of various chemical gradients and pressures, creating an environment that might mimic the ancient Hadean seas. However, the delicate nature of these structures poses significant challenges for scientists, as they are not only fragile but also difficult to analyze due to the inability to measure local conditions accurately within the structures or to extract them without damage. The figure above shows chemical gardens depicted in (a-c) laboratory conditions, and in the Lost City Hydrothermal Vent field in the mid-Atlantic Ocean (lower image).
Project Description: Velling's project aims to leverage the advanced 3D printing technology at the KNI to create complex, porous structures that simulate hydrothermal chimneys, which are crucial to understanding the chemical origins of life. These artificial chimneys are designed to be highly porous and can withstand the high-pressure variances similar to those in deep-sea environments. The scaffolds will be made from pre-ceramic polymer materials, such as Alumina 4N, known for their high thermal and chemical stability, allowing for the adsorption of iron, molybdenum, and other mineral species, as well as the passage of alkaline fluids mimicking the natural process of mineral deposition in hydrothermal vents.
The project is structured into three stages: The first involves designing the scaffolds with built-in spaces for sensors and electrodes to monitor conditions like pH and temperature. These designs will be iteratively refined to balance porosity and structural integrity under the guidance of KNI staff, including Alex Wertheim. The second stage takes place at NASA/Caltech's Jet Propulsion Laboratory, where the team will conduct experiments using these scaffolds to better understand the precipitation of minerals and their interactions with various organic and inorganic compounds.
In the final stage, successful scaffold structures that exhibit the desired properties and catalytic efficiencies will undergo a series of detailed analyses. Techniques like cyclic voltammetry, electrochemical impedance spectroscopy, nuclear magnetic resonance spectroscopy, and X-ray diffraction will be used to scrutinize the electrochemical and structural characteristics of these synthesized hydrothermal vent analogues. The aim is to closely observe the crystallization patterns and the reaction interfaces, providing insights into the mineralogical and chemical processes that may occur on ocean worlds. This collaborative effort among Caltech and JPL researchers and KNI staff strives to deepen our understanding of astrobiological processes and the potential for life-supporting conditions in extraterrestrial environments.