Revolutionary Sensor Boosts Accuracy in Liquids

Penn State researchers develop a graphene-based field-effect transistor that is up to 20 times more sensitive than traditional sensors.

Mar. 18, 2026 at 12:54am

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Researchers at Penn State have designed a new type of field-effect transistor using graphene that can facilitate responsive and versatile sensing, even in liquid-rich environments like the human body. The team's sensors were up to 20 times more sensitive to various chemical and biological signals compared to other sensors built with comparable transistor designs.

Why it matters

Accurately measuring small shifts in biological markers or harmful chemicals in water supplies can identify critical problems before they impact patients or the environment. However, existing sensors often struggle with signal drift and instability when exposed to liquids, limiting their reliability. This new graphene-based transistor design aims to overcome those limitations.

The details

The technology is based on graphene, a highly conductive and sensitive 2D material. Field-effect transistors used in biosensors have traditionally been made with silicon, but are increasingly using 2D materials like graphene. However, when immersed in liquid, these transistors face signal drift and electrical leakage, lowering their accuracy. The Penn State team adjusted the design to have two gates rather than one, allowing them to keep the current running through the system constant and remove a primary cause of signal drift. They also added a feedback system to one of the gates to more accurately track the impact of molecules on the sensor's voltage.

  • The research was published in March 2026 in the journal npj 2D Materials and Applications.

The players

Aida Ebrahimi

Thomas and Sheila Roell Early Career Associate Professor of Electrical Engineering at Penn State, and the corresponding author of the research paper.

Vinay Kammarchedu

An electrical engineering doctoral candidate at Penn State and the first author on the research paper.

Penn State

The university where the research was conducted.

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What they’re saying

“Aside from signal drift, these devices struggle with electrical leakage and the instability caused by sweeping, a common measurement technique that substantially impacts their reliability over time. This makes it difficult to apply these transistors in biointerfaces, like implantable devices, or in any interaction that interfaces with fluid.”

— Aida Ebrahimi, Thomas and Sheila Roell Early Career Associate Professor of Electrical Engineering (npj 2D Materials and Applications)

“We adjusted the design to have two gates rather than one, allowing us to have independent control over the amount of current flowing through the system. Using two gates, we can keep the current running through the system constant, removing a primary cause of signal drift. On top of that, we added a feedback system to one of the gates to more accurately track the impact that molecules have on the sensor's voltage.”

— Vinay Kammarchedu, Electrical engineering doctoral candidate (npj 2D Materials and Applications)

What’s next

The researchers plan to further develop and test the new graphene-based field-effect transistor design to improve its sensitivity and stability for potential use in a variety of liquid-based sensing applications, including medical diagnostics and environmental monitoring.

The takeaway

This innovative graphene-based sensor technology represents a significant advancement in overcoming the limitations of traditional field-effect transistors when used in liquid environments. If successfully developed, it could enable more accurate and reliable monitoring of critical biological and environmental markers, with far-reaching implications for healthcare and environmental protection.