Accelerating discovery in battery materials, clean energy catalysts, and pharmaceutical development through high-throughput experimentation
In the world of chemical research, progress has often been measured one painstaking experiment at a time. For scientists working in electrochemistry—the field that uses electricity to drive chemical reactions—this slow pace has been a significant hurdle. Discovering new materials for batteries, screening catalysts for clean energy, or developing new methods for drug synthesis requires testing countless combinations of conditions, a process that can take years with conventional equipment. While other scientific fields have embraced high-throughput automation, allowing them to run hundreds of tests simultaneously, electrochemistry has lagged behind, constrained by instruments that could only handle a few experiments at once 1 .
To appreciate Legion's innovation, it's helpful to understand what it aims to replace. Traditional electrochemical research has relied largely on two approaches:
Using a single potentiostat (the "control center" of an electrochemical experiment) to test conditions one after another. This is reliable but incredibly slow 1 .
Running multiple working electrodes simultaneously, but with a major caveat—they all share the same electrolyte bath and are subjected to the same electrical potential. This is faster but severely limits the types of questions a scientist can ask 1 .
Each of the 96 working electrodes can be controlled independently
No cross-contamination between experiments
All 96 experiments run at the same time, not sequentially
Legion's design is a marvel of interdisciplinary engineering, seamlessly blending hardware and software to manage its complex tasks 1 :
The heart of Legion is a custom-built 96-cell array. Each cell consists of a machined polyether ether ketone (PEEK) top that defines the solution volume, a polydimethylsiloxane (PDMS) gasket for sealing, and a glassy carbon plate that serves as the working electrode. Each cell holds a maximum volume of 500 μL and features its own quasi-reference counter electrode (QRCE) 1 .
This is where Legion truly stands apart. Each of the eight QRCEs in a column connects to an 8-channel potentiostat board. Twelve of these boards interface with a field-programmable gate array (FPGA), which provides individual control over the potential applied to each QRCE and independently measures the current flowing through each one. This setup allows researchers to run 96 different reaction conditions, potential waveforms, or experimental protocols all at the same time 1 .
As configured, the instrument operates with a voltage range of ±4 V, a current range of ±250 μA, and a remarkable current resolution of 8 nA, providing precise measurement for even subtle electrochemical processes 1 .
To illustrate Legion's capabilities, let's examine how researchers used it to screen electrocatalytic dehalogenation reactions—processes that remove halogen atoms (like iodine or bromine) from molecules using electricity. This type of reaction is particularly important in pharmaceutical synthesis and environmental remediation of halogenated pollutants 1 .
The researchers designed an experiment to test the efficiency of different catalysts in removing iodine from various organic compounds 1 :
Each of the 96 electrochemical cells was filled with an organic solvent containing the electrolyte tetramethylammonium tetrafluoroborate (TMABF4), along with different combinations of substrate molecules and potential catalysts.
The glassy carbon working electrode was polished and cleaned before assembly. A Ag/AgCl quasi-reference counter electrode was used for each cell.
The team applied a specific reductive potential waveform across all 96 cells simultaneously, each containing different reaction mixtures.
After the electrochemical reactions were complete, the solutions were analyzed using high-throughput mass spectrometry (MS) to identify and quantify the reaction products.
The experiment demonstrated Legion's power for rapid reaction screening. The system successfully identified which catalyst-substrate combinations most effectively removed iodine atoms, generating a rich dataset that would have taken weeks to acquire using conventional methods.
| Substrate Name | Abbreviation | Chemical Structure |
|---|---|---|
| 2-iodo-N-methylacetamide | IMA | Halogenated amide |
| 1-iodooctane | IO | Halogenated alkane |
| 2-iodo-N-phenylacetamide | IPA | Halogenated anilide |
| 2-bromo-N-phenylacetamide | BPA | Brominated analogue |
Table 1: Example Substrates Used in Dehalogenation Screening
| Parameter | Traditional Serial Method | Legion Platform |
|---|---|---|
| Experiments per run | 1 | 96 |
| Estimated time for 96 conditions | ~1 week | ~1 hour |
| Solution volume per experiment | 10-100 mL | 200-500 μL |
| Individual control | Possible with multiple instruments | Built-in |
| Cross-contamination risk | High with serial testing | Minimal |
Table 2: Performance Metrics of Legion vs. Traditional Methods
The data revealed how subtle changes in molecular structure—switching from an iodine to a bromine atom, or modifying the organic backbone—significantly impacted reaction efficiency. This level of screening is invaluable for designing more efficient synthetic routes in pharmaceutical chemistry or identifying optimal conditions for breaking down environmental contaminants 1 .
Legion's value extends beyond mere speed—it generates data of a different character and quality than traditional methods. Because all 96 experiments run under nearly identical conditions simultaneously, researchers can make direct comparisons without worrying about instrumental drift or day-to-day environmental variations that can plague serial experiments.
| Parameter | Specification | Significance |
|---|---|---|
| Number of cells | 96 | Matches standard microtiter plate format |
| Working electrode material | Glassy carbon | Versatile for various reactions |
| Operating voltage range | ±4 V | Suitable for most organic transformations |
| Current resolution | 8 nA | Detects even small-scale reactions |
| Minimum practical volume | 200 μL | Reduces reagent consumption and cost |
| Reference electrode | Ag/AgCl or Ag/AgO QRCE | Provides stable potential control |
Table 3: Key Technical Specifications of the Legion Instrument
This data density has particular significance for machine learning and artificial intelligence in chemistry. By generating consistent, high-quality datasets across multidimensional reaction spaces, Legion provides the training data needed to build predictive models that can guide future experimentation, potentially leading to fully autonomous discovery systems 6 .
A typical Legion experiment, like the dehalogenation screening study, relies on a carefully selected set of chemical reagents and materials 1 :
| Reagent/Material | Function in Experiment | Specific Example |
|---|---|---|
| Supporting Electrolyte | Conducts electricity without participating in reaction | Tetramethylammonium tetrafluoroborate (TMABF4) |
| Redox Probes | Validates instrument performance | Potassium ferricyanide, Ruthenium hexaammine |
| Substrate Molecules | Target compounds for transformation | 1-iodooctane, 2-iodo-N-phenylacetamide |
| Quasi-Reference Counter Electrode | Provides stable reference potential | Ag/AgCl wire |
| Solvent Systems | Medium for reactions | Aqueous buffers, Organic solvents like acetonitrile |
| Polishing Materials | Maintain electrode surface quality | Alumina slurries (0.3 to 0.05 μm) |
Table 4: Key Research Reagent Solutions
Legion represents more than just a sophisticated instrument—it embodies a new approach to electrochemical research. By dramatically reducing the time and resources needed to explore complex reaction spaces, it empowers scientists to ask bolder questions and pursue more ambitious research programs.
Recent developments suggest this is just the beginning. Researchers are already working to integrate Legion with other high-throughput analysis techniques, creating fully automated discovery pipelines that can screen reactions and analyze products with minimal human intervention 4 .
Similar platforms using light-powered wireless electrodes are also emerging, further expanding the toolbox for electrochemical discovery 5 . These innovations promise even greater flexibility and scalability for high-throughput experimentation.
As high-throughput methods become more accessible, we can anticipate accelerated progress in critical areas like sustainable energy storage, green chemical synthesis, and pharmaceutical development.