Researchers Create a Unique Transistor Device based on Neural Function

November 13, 2020 by Stephanie Leonida

Researchers from the University of Surrey developed a unique transistor that could provide greater design freedom and simplified circuitry for next-generation electronic devices.

Recent research by investigators from the University of Surrey has unveiled a unique transistor design that could change the way electronic circuits are constructed. This may bring forward the next-generation electronic devices, from enhanced consumer wearables and gadgets to eco-disposable sensors. 

The researchers from Surrey published their findings in the journal Advanced Intelligent Systems, where they detail how the nature of their device, coined the multimodal transistor (MMT) could make it a key player in transistor technology. 


Design layout of the multimodal transistor.
Design layout of the multimodal transistor. Image used courtesy of the University of Surrey


What is a Multimodal Transistor?

Conventional metal-oxide-semiconductor field-effect (MOSFET) transistors seen on today’s market are non-linear in their design. This itself hinders design freedom and complicates evaluation. Usually, a gate electrode is used to control the analog and digital operations through the application of a certain voltage. 

Digitally, this voltage turns the transistor on or off. With regard to the analog operations, gate-to-source voltage allows characteristics such as gain and transconductance to be set. Traditional floating gate transistor designs can suffer from certain complications that can reduce the clarity and repeatability of signals. 

The nature of on/off switching mediated by the Surrey team’s MMT is a key factor that could potentially enable more flexible and simplified electronic circuit designs in the future. The switching is controlled independently from the amount of current passing through the device structure. This means that the MMT is able to function at a higher speed than conventional transistors. 

Additionally, the device has a linear dependence on output and input. For engineers, this is a highly desirable feature, because it allows the creation of complex circuitry but with fewer circuit elements. The digital to analog converter is compact, enabling engineers to perform multilevel logic and multiplication. The researchers at Surrey said that the functionality offered by the MMT would otherwise be conducted by larger, less compact circuits. 

In a recent news release Dr. Radu Sporea, Project Lead and Senior Lecturer in Semiconductor Devices at the University of Surrey commented on the research: “Our Multimodal Transistor is a paradigm shift in transistor design. 

It could change how we create future electronic circuits. Despite its elegantly simple footprint, it truly punches above its weight and could be the key enabler for future wearables and gadgets beyond the current Internet of Things.”


The MMT allows for a linear dependence on output and input.
The MMT allows for a linear dependence on output and input. Image used courtesy of the University of Surrey


Operation in a Floating Gate Configuration

By utilizing the MMT in a floating gate configuration, disturbance to current injection is shielded by floating gates situated above the drain chain channel. In essence, this serves to improve output impedance and gain, which is not readily achieved in contact control transistors. 

Analog charge storage on floating gates may be a step forward to more advanced artificial intelligence (AI), neural network decision, and classification circuits.