Diamonds Finally Find Footing on the Semiconductor Stage—for Rapid COVID-19 TestingApril 22, 2020 by Tyler Charboneau
COVID-19 test results currently take 5–15 minutes of processing time. But diamond-based Bio-FETs could slash that time to mere seconds.
COVID-19 testing has been rife with complexities with companies scrambling to bring new testing measures to market. While home testing availability has improved, laboratory and point-of-care diagnosis have lagged behind public demand. One Illinois company now hopes to turn the tide.
AKHAN Semiconductor's diamond processes include microwave plasma and hot filament CVD for electronics, thermal applications, and optics. Image used courtesy of AKHAN Semiconductor
AKHAN Semiconductor is known for its use of diamonds as wide band-gap semiconductors (WBG) for computing technology.
But now, the company is utilizing its Miraj Diamond Platform to fast track the development of COVID testing devices. According to AKHAN, the hyper-conductive material will solve many existing issues with scalability, pricing, and testing speed.
Bio-FETs Provide Test Results in Seconds
AKHAN views its materials technology as a linchpin in applications that use biosensing field-effect transistors (Bio-FETs). Bio-FET devices, which are based on the MOSFET structure, use biosensing components to analyze viral agents. Bio-FETs are a type of ion-sensitive field-effect transistor (ISFET). These replace traditional metallic gates with electrolyte solutions.
AKHAN’s unique Bio-FET solution is tunable for both gas and liquid suspensions, making it suitable for biological analysis. It can also operate at temperatures exceeding 300°C.
Diagram of a typical Bio-FET, showing a biological receptor structure. Image (modified) used courtesy of Huijunan [CC BY-SA 4.0]
While other rapid tests for COVID-19 can assess infection in five to fifteen minutes, Bio-FET systems can deliver results in mere seconds. Scientists have leveraged these instant results to test for Ebola and SARS. COVID is 86% analogous with SARS (another coronavirus), making it a natural addition to that list.
Tackling the Lingering Drawbacks of Bio-FETs
The structural integrity of Bio-FET systems has been a lasting pain point. Internal and external components are sensitive. By comparison, AKHAN Semiconductor says Miraj Diamond handles high temperatures much more readily while offering greater longevity. The company also claims that Miraj components achieve this at 1/1000th the thickness of competing solutions.
However, integrating the core technology wasn’t without its hiccups. CEO Adam Khan explains, “The major challenges were strong and sensitive attachment of the antibody linker layer…to the electronic device design.”
A Miraj Diamond laser lens. Image used courtesy of AKHAN Semiconductor
That layer forms “the unique biological aspect of the device.” Nanocrystalline diamonds are biocompatible with blood, viruses, and antibodies.
Professionals must sterilize device components between tests. Diamond components can withstand repeated treatment with harsh chemicals, boosting their long-term usability.
Testing machines are intricate—both virus detection and electrical systems must be optimized. AKHAN says their diamond material isolates voltages with ease, making it useful for highly-demanding applications. AKHAN also states that diamond semiconductors operate with at least 90% greater efficiency than alternative solutions. Power retention is key.
Semiconductor Companies Shift Their Sights to COVID-19 Relief
The COVID-19 outbreak has impacted semiconductor manufacturing on a large scale. Many companies have shifted regular operations to designing ventilators and testing equipment. We asked AKHAN Semiconductor how they foresaw production shifting as a result of the pandemic. Khan responded, “We anticipate up to 50% of our production volume shifting to COVID-related devices over the next 3 years.”
An immediate ramp-up is anticipated, yet AKHAN has prioritized longstanding COVID-19 detection. Khan also expects demand for Miraj Diamond components to swell: “Demand will grow exponentially and we are prepared to expand our manufacturing to accommodate the demand curve, greater than 10,000,000 parts per year.”
Miraj Diamond. Image used courtesy of AKHAN Semiconductor
Considering that over 329 million residents live in the United States, that level of production is sorely needed. Access to testing is crucial, so who will benefit? Khan hopes the promising scalability of diamond solutions will facilitate “mass commercialization for point-of-care and environmental monitoring.”
Universal testing won’t happen overnight, nor will mass commercialization. Existing biosensor diagnostic OEMs will be the early adopters of these components, according to Khan. The company aims to pursue widespread sales—once existing bottlenecks are resolved and optimistic feedback rolls in.
Diamonds Flex Their Conductivity Over Copper and Silicon
AKHAN Semiconductor claims that its Miraj Diamond can improve traditional semiconductor designs. Produced using a 200 mm semiconductor process, the Miraj Diamond is created by harnessing methane gas as an input, leading to diamond wafer production. Methane cracking across a heated surface (via plasma ball) is an essential step. The AKHAN facility is also equipped for swift, in-house prototyping and testing.
The company claims its diamond nanomaterials are five times more conductive than copper. They also conduct heat 22 times better than silicon. It takes a relatively-minute amount of material to achieve the same performance seen in traditional materials. Fifty times less diamond than silicon is required to isolate 10,000 volts.
Performance of various power semiconductors. Image used courtesy of AKHAN Semiconductor
Beyond COVID-19 testing, AKHAN foresees its diamond semiconductors making a splash among all industries—with notable applications including "faster supercomputers, advanced radar and telecommunications, hyper-efficient hybrid vehicles, electronics in extreme environments, and next-generation aerospace and avionics."
In a past article, AAC contributor Robert Keim mentioned that in many ways, diamond as a semiconductor of the future was still in the theoretical realm. But perhaps this use case of AKHAN's laboratory diamonds may be the long-awaited key to extensive COVID-19 testing.
Aside from SiC and GaN, which are becoming increasingly widespread, which wide band-gap semiconductors show the most promise in your mind? Share your thoughts in the comments below.