Overview

Engineering at the grain boundary - the meeting points of where the crystals or grains of varying size and orientation that comprise a material meet—is crucial to fully utilizing a new material. This area of research is pivotal to fully utilizing the mechanical, electrical, and thermal transport properties of a variety of materials. However, precision grain-boundary engineering is difficult to achieve with current top-down methods.

Ou Chen has invented a process for creating bulk grain-boundary materials from colloidal metal nanocrystals, using surface ligand engineering followed by a pressure sintering process. The resulting materials possess the appearance and conductivity of a metal while maintaining the characteristics of the nanocrystal building blocks.

Market Opportunity

Today’s methods for grain-boundary engineering include electrodeposition, hammering, mechanical alloying, spark erosion, rapid cooling, and sputtering. All these top-down approaches lack precise control of grain boundary conditions. A method for fabricating materials with precisely designed GB conditions would allow engineering to overcome a fundamental hurdle in advancing ground-boundary materials for a variety of practical applications.

Innovation and Meaningful Advantages

Our invention starts with a pressure-sintering method that transforms metal nanocrystals into free-standing grain-boundary materials at the centimeter scale. This method of bottom-up fabrication, which Chen’s team calls an “NC coining” process, involves a ligand exchange of the synthesized metal NCs to replace the native organic capping ligands with small, inorganic ones, followed by a ligand and solvent removal process through washing and drying. The resulting solid NC powder can then go through a pressure sintering step to generate the final bulk GB NC-coins.

This method could be used to produce nano-structured materials with custom grain-boundary conditions, allowing for the optimization of high-hardness materials, strong and anti-corrosive coating materials, as well as solar cell, photovoltaic, phonon-voltaic, electrode, magnetic, spintronics, battery, and optical materials.

Collaboration Opportunity

We are seeking an investment opportunity to further develop this innovative technology.

Principal Investigator

IP Information

US Patent 11,607,733, Issued March 11, 2023

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