Rare Earth elements (REEs)Developing Cohesive, Domestic Rare Earth Element Technologies

Published 15 July 2021

The U.S. has adequate domestic REE resources, but its supply chain is vulnerable due to dependence on foreign entities for separation and purification of these elements. DARPA program aims to fortify supply chain by utilizing bioengineering approaches to facilitate REE separation and purification.

Rare Earth Elements (REEs) are a group of 17 similar metals that are critical material components of many DoD systems, including lasers, precision-guided weapons, magnets for motors, and other devices. Although the U.S. has adequate domestic REE resources, its supply chain is vulnerable due to dependence on foreign entities for separation and purification of these elements. “Biomining,” an approach that uses microbes to extract or separate target metals like gold or copper from a variety of sources is not yet useful for REEs because of poor specificity and selectivity of the microbes for REEs. The Environmental Microbes as a BioEngineering Resource (EMBER) program aims to leverage advances in microbial and biomolecular engineering to develop a scalable bio-based separation and purification strategy for REEs using under-developed domestic sources.

“The EMBER program will aim to fill a critical DoD supply chain gap” stated Dr. Linda Chrisey, EMBER program manager. “The program will target the development of bioengineered organisms/biomolecular approaches for REE purification, then translate these to practical biomining modules (e.g., biosorbent, biofiltration) that can be integrated with domestic REE sources.”

The four-year program will address two Technical Areas (TAs) and be divided into three phases. The goal of TA1, “Bioengineering for REE Utilization,” is to establish a platform for engineering organisms and/or biomolecules to enable the binding of REEs under harsh conditions. TA2, “REE Biomining” will focus on developing and testing a biomining workflow to purify individual REEs from actual source materials. Teams must propose to both TAs to develop comprehensive, enduring solutions.

During Phase 1, efforts will focus on developing microorganisms and biomolecules suitable for use in REE separation – a challenging task due to the chemical similarity between REEs. In Phase 2, performers will work on improving the efficiency and scale of REE separation from actual source materials. Phase 3 will culminate in an aggressive, pilot-scale REE biomining demonstration. Throughout the program, the teams will work with an Independent Verification and Validation (IV&V) team established by DARPA.

EMBER aims to deliver multiple capabilities, such as the separation of REE mixtures into individual elements; inter-conversion of REE salts/oxides to facilitate production of manufacturing-ready forms; and new assays for high-throughput analysis of REE-containing cells and biomolecules,” added Chrisey.

Additional details of the program schedule and metrics are available in the broad agency announcement at https://sam.gov/opp/8e7c7d2a79774a8d89e13068c8c6cb54/view.