This startup wants to kick-start a molecular electronics revival
In 1999, Rice University chemist Jim Tour co-founded Molecular Electronics Corporation, a company that aimed to use single molecules to make a new type of electronic memory. But Tour had even bigger dreams. In a 2000 story in Wired, he foretold a future in which molecular electronics would leapfrog silicon-based circuitry, allowing computer chips to keep getting denser and more powerful. This vision was short-lived. Five years later, flash had dominated the memory market and silicon continued to be the dominant chip technology. Tour then left the molecular electronic business. The once-well-funded field almost collapsed.
Now, Roswell Biotechnologies, a San Diego-based startup, hopes to give molecular electronic a second chance. Tour, who is on Roswell’s scientific advisory boards, is ready to defend it again. He says, “I’ve been saying all along this thing can work.”
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“It’s a great concept. It’s time for chip manufacturers to do something in biosciences,” says Nils Wale, a chemist from the University of Michigan. He is co-founder of aLight Science, a company that develops single molecules as biosensors. However, its approach is to use fluorescence (or the emission of light) to read the results.
Roswell are not the only companies that are interested in chip-based biosensors. Dynamic Biosensors, which is based in Munich offers chips that have DNA-based sensors that use light. Merriman states that Roswell’s manufacturing process produces precise sensors that can be mass-produced using modern chip-making techniques.
The centerpiece of Roswell’s circuits is a molecularwire made from a chain amino acids and connected to the rest as a regular metal wire. The lab attaches a molecule on the other end of the wire to create a sensor. The molecule’s electrical conductivity changes when it interacts with its target, which can be a strand or DNA, or any other biologically relevant molecules. Software extracts the interaction details from the chip that records this change.
To assemble thousands of sensors, Roswell starts with a silicon chip studded with prefabricated nanoelectrodes, then uses electric voltage to pull molecules out of solution and onto the chip. This part of the assembly process takes under 10 seconds; in the past, similar molecular processes took hours or even days.
Roswell’s approach could revive some of the hopes molecular electronics researchers had 20 years ago. It seemed that the small size molecules could make circuit components smaller and computational chips more dense. It is interesting to note that a molecular chipsmaker could in principle “self-assemble” circuits by adding molecules under highly controlled conditions and letting the molecules assemble themselves into the desired structures. George Church, a Harvard geneticist, and a member Roswell’s scientific advisory boards, says.
Excitement about such molecular properties led to a rapid growth of the molecular electronics field in the late 1990s. It seemed like the perfect moment. “There were all these predictions all through the ’80s and ’90s, about how silicon was going to hit a brick wall,” Tour recalls. It didn’t happen. Engineers kept pushing forward. “We weren’t shooting at a static target. He says that silicon just kept improving its performance. Philip Collins, a physicist at the University of California, Irvine, who has previously consulted for Roswell, says the ensuing downfall of molecular electronics was rather dramatic: “I would say nine out of 10 researchers dropped out.”
With the new chip, Roswell is instead targeting an application for which silicon is ill-suited. Collins says that molecules are more complex than binary because they can encode all kinds of different states. “They can encode all the interesting different states, such as in biochemistry that we just don’t have other ways to access,” Collins says.
Roswell’s new vision is of biosensors that would allow people to check in on biomarkers such as vitamin levels or evidences of infection with only a little bit more hassle than checking their heart rate on a smartwatch. Roswell’s case would allow thousands of biosensors to detect different molecular interactions simultaneously. The chips would also be disposable.
University of Michigan’s Walter notes that though Roswell’s device can accommodate more than 10,000 biosensors on one chip, having hundreds of thousands, or millions, more would push the device toward a more marketable functionality, especially when it comes to detecting low concentrations of biomarkers in early disease.
The commercial biotechnology market is not a new arena for Church, Merriman, and other company leaders. The Roswell team’s expertise and experience has not made the company’s financing journey as simple as Paul Mola had hoped. Mola said that he expected venture capital would flood in after the company’s January paper. Although Roswell has raised more than $60 million so far, primarily from strategic investors and representatives of wealthy families, it had to nearly halve its workforce in February.
Mola is disappointed by the lackluster investment in the company, which he claims is so close to commercialization. He says, “We feel that our company has done a lot with very little.” “Now we really need the community to step up and support us and take us all the way.”
Mola, who is Black, says part of the problem lies with the biotech industry’s troublesome track record with diversity–a concern that Stat reported in early March. If you think about entrepreneurs and founders, they have a tendency to have an entrepreneur in their families, and they have access to networks and investors. He says that Black founders lack this fundamental and systemic perspective. “I don’t possess that.”
Roswell still has a chance to release a commercial device before the end of this year, Mola states. The startup is about start its next funding series. It will also be introducing a service that could attract customers before it is possible for them to sell chips directly to them: scientists can now send samples to Roswell to have its molecular sensors work on them in-house, gathering valuable data about, such as, the function of new drugs in real time.
For Tour, Roswell’s work continues to be a symbol of the rebirth of molecular electronics: “It’s nice to be able to see something happen and to say, OK, it did work, we just took longer than we thought.”
Karmela Padavic-Callaghan is a freelance journalist based in Brooklyn, New York.
I’m a journalist who specializes in investigative reporting and writing. I have written for the New York Times and other publications.