Bringing signals into phase

September 26, 2017, King Abdullah University of Science and Technology
Blending polymer materials in the right combination can create fractional-order capacitors that are compatible with printed circuit boards. Credit: KAUST

How we use and generate electricity has changed dramatically over the past century yet the basic components that control its flow remain remarkably similar. Researchers at KAUST have now developed a novel type of component that could improve the performance of electrical circuits.

Electronic circuitry is traditionally constructed from three primary elements; a resistor, a and an inductor. A sinusoidal electrical signal passing through these devices will change in , or amplitude, and the relative timing of the crest of the wave, known as its . A resistor will change amplitude only while a capacitor and an inductor can also change phase, but only by exactly one quarter of the length of the wave, or 90°.

Components that could alter the phase of the electrical signal by a different amount would enable with more varied functionality. One such , known as a fractional-order capacitor, was realized by electrical engineering doctoral student Agamyrat Agambayev, under the supervision of Hakan Bagci and Khaled Salama, and colleagues. "We use a solution-casting method to fabricate fractional-order capacitors," explains Salama. "This method allows us to easily blend different polymers and provide a mechanism to tune the device's properties."

Numerous approaches to creating a fractional-order capacitor have been demonstrated in the past but all have drawbacks. Using a liquid medium, for example, results in large devices that cannot be integrated with microelectronic circuits. Ideally, a fractional-order capacitor should be made from a dielectric material that is compatible with printed-circuit-board technology. It should also operate over a wide range of signal frequencies and have a controllable phase change, known as the constant phase angle or CPA.

The KAUST team have created a fractional-order capacitor using a polymer based on poly (vinylidene fluoride). They deposited a thin film on a layer of gold on a silicon substrate. The film was patterned as required and bonded to the printed circuit board to create the final device. The electrical properties of the polymer were controlled using a simple solution-mixing approach to add different amounts of trifluoroethylene and/or cholorfluroethylene. They could tune the CPA of their devices from between 66 and 88 degrees depending on the blend composition. What's more, the devices acted over a wide range of frequencies from 0.1 to 10 megahertz.

The team has previously created graphene fractional-order capacitors, but they believe the tunablility offered by polymers represents a huge advance. "Next, we will look into modeling these structures to better understand their behavior," says Bagci. "This will help design fractional capacitors with better performance."

Explore further: New diode features optically controlled capacitance

More information: Agamyrat Agambayev et al. Ferroelectric Fractional-Order Capacitors, ChemElectroChem (2017). DOI: 10.1002/celc.201700663

Related Stories

New diode features optically controlled capacitance

June 6, 2017

A team of researchers at the Israel Institute of Technology has developed a new capacitor with a metal-insulator-semiconductor (MIS) diode structure that is tunable by illumination. The capacitor, which features embedded ...

3Qs: Could circuits' face-lift mean faster, smaller phones?

January 15, 2014

Imagine a cell phone that's half the size with longer battery time and better performance. That could become a reality thanks to new research by Nian Sun, associate professor of electrical and computer engineering at Northeastern. ...

Fractional calculus helps control systems hit their mark

December 23, 2016

If you've ever searched for ways to curb your car's gas-guzzling appetite, you've probably heard that running on cruise control can help reduce your trips to the pump. How? Cars, it turns out, are much better than people ...

Recommended for you

A novel approach of improving battery performance

September 18, 2018

New technological developments by UNIST researchers promise to significantly boost the performance of lithium metal batteries in promising research for the next-generation of rechargeable batteries. The study also validates ...

Germany rolls out world's first hydrogen train

September 17, 2018

Germany on Monday rolled out the world's first hydrogen-powered train, signalling the start of a push to challenge the might of polluting diesel trains with costlier but more eco-friendly technology.

Technology streamlines computational science projects

September 15, 2018

Since designing and launching a specialized workflow management system in 2010, a research team from the US Department of Energy's Oak Ridge National Laboratory has continuously updated the technology to help computational ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.