Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pushing 'print' on large-scale piezoelectric materials

07.09.2018

First ever large-scale 2D surface deposition of piezoelectric material

First ever large-scale 2D surface deposition of piezoelectric material
--Simple, inexpensive technique opens new fields for piezo-sensors & energy harvesting


Atomic force microscopy imaging of 2D GaPO4 and piezoelectric measurements at varying applied voltages

Credit: FLEET

Researchers have developed a revolutionary method to 'print' large-scale sheets of two dimensional piezoelectric material, opening new opportunities for piezo-sensors and energy harvesting.

Importantly, the inexpensive process allows the integration of piezoelectric components directly onto silicon chips.

Until now, no 2D piezoelectric material has been manufactured in large sheets, making it impossible to integrate into silicon chips or use in large-scale surface manufacturing.

This limitation meant that piezo accelerometer devices - such as vehicle air bag triggers or the devices that recognise orientation changes in mobile phones - have required separate, expensive components to be embedded onto silicon substrates, adding significant manufacturing costs.

Now, FLEET researchers at RMIT University in Melbourne have demonstrated a method to produce large-scale 2D gallium phosphate sheets, allowing this material to be formed at large scales in low-cost, low-temperature manufacturing processes onto silicon substrates, or any other surface.

Gallium phosphate (GaPO4) is an important piezoelectric material commonly used in pressure sensors and microgram-scale mass measurement, particularly in high temperatures or other harsh environments.

"As so often in science, this work builds on past successes," lead researcher Professor Kourosh Kalantar-zadeh explains. "We adopted the liquid-metal material deposition technique we developed recently to create 2D films of GaPO4 through an easy, two-step process."

Professor Kalantar-zadeh, now Professor of Chemical Engineering at UNSW, led the team that developed the new method while Professor of Electronic Engineering at RMIT University. The work was materialised as a result of significant contribution from RMIT's Dr Torben Daeneke and extreme persistence and focus shown by the first author of the work, PhD researcher Nitu Syed.

The revolutionary new method allows easy, inexpensive growth of large-area (several centimetres), wide-bandgap, 2D GaPO4 nanosheets of unit cell thickness.

It is the first demonstration of strong, out-of-plane piezoelectricity of the popular piezoelectric material.

THE TWO-STEP PROCESS

  1. Exfoliate self-limiting gallium oxide from the surface of liquid gallium made possible by the lack of affinity between oxide and the bulk of the liquid metal
  2. 'Print' that film onto a substrate and transform it into 2D GaPO4 via exposure to phosphate vapour.

APPLICATIONS

The new process is simple, scalable, low-temperature and cost effective, significantly expanding the range of materials available to industry at such scales and quality.

The process is suitable for the synthesis of free standing GaPO4 nanosheets. The low temperature synthesis method is compatible with a variety of electronic device fabrication procedures, providing a route for the development of future 2D piezoelectric materials.

This simple, industry-compatible procedure to print large surface area 2D piezoelectric films onto any substrate offers tremendous opportunities for the development of piezo-sensors and energy harvesters.

PIEZOELECTRIC MATERIALS

These are materials that can convert applied mechanical force or strain into electrical energy. Such materials form the basis of sound and pressure sensors, embedded devices that are powered by vibration or bending, and even the simple 'piezo' lighter used for gas BBQs and stovetops.

Piezoelectric materials can also take advantage of the small voltages generated by tiny mechanical displacement, vibration, bending or stretching to power miniaturised devices.

THE MATERIAL: GALLIUM PHOSPHATE (GaPO4)

Gallium phosphate is a quartz-like crystal used in piezoelectric applications such as pressure sensors since the late 1980s, and particularly valued in high-temperature applications. Because it does not naturally crystallise in a stratified structure and hence cannot be exfoliated using conventional methods, its use to date has been limited to applications that rely on carving the crystal from its bulk.

###

THE STUDY

Printing two-dimensional gallium phosphate out of liquid metal is published in Nature Communications this week (DOI 10.1038/s41467-018-06124-1).

Test materials were synthesised in RMIT's Micro Nano Research Facility (MNRF) using van der Waals exfoliation followed by a chemical vapour phosphatisation.

Measurements included Piezo-force microscopy (PFM), which confirmed a high out-of-plane piezoelectric coefficient of 8-10 pm/V, confirmed by density functional theory (DFT) calculations.

This is sufficiently high to provide promise for us in 2D-material based piezotronic sensing and energy harvesting.

Acknowledgements As well as FLEET funding via the Australian Research Council Centres of Excellence program, facilities and technical assistance were provided by the RMIT Micro Nano Research Facility (MNRF) and RMIT Microscopy and Microanalysis Facility (RMMF). Computational resources were provided by the Australian Government's National Computational Infrastructure National Facility and the Pawsey Supercomputer Centre.

NOVEL MATERIALS RESEARCH AT FLEET

Novel and atomically-thin (2D) materials with useful electronic properties are studied at FLEET, an Australian Research Council Centre of Excellence, for their potential use in new 'beyond CMOS' electronic devices.

The Centre for Future Low-Energy Electronics Technologies (FLEET) brings together over a hundred Australian and international experts, with the shared mission to develop a new generation of ultra-low energy electronics.

The impetus behind such work is the increasing challenge of energy used in computation, which uses 5-8% of global electricity and is doubling every decade.

MORE INFORMATION

--Contact Professor Kourosh Kalantar-zadeh k.kalantar-zadeh@unsw.edu.au

--Connect @FLEETCentre

--Visit FLEET.org.au

--Contact FLEET media@FLEET.org.au

--Subscribe FLEET.org.au/news

Errol Hunt | EurekAlert!

More articles from Materials Sciences:

nachricht Scientists create a nanomaterial that is both twisted and untwisted at the same time
16.09.2019 | University of Bath

nachricht New metamaterial morphs into new shapes, taking on new properties
12.09.2019 | California Institute of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tomorrow´s coolants of choice

Scientists assess the potential of magnetic-cooling materials

Later during this century, around 2060, a paradigm shift in global energy consumption is expected: we will spend more energy for cooling than for heating....

Im Focus: The working of a molecular string phone

Researchers from the Department of Atomically Resolved Dynamics of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg, the University of Potsdam (both in Germany) and the University of Toronto (Canada) have pieced together a detailed time-lapse movie revealing all the major steps during the catalytic cycle of an enzyme. Surprisingly, the communication between the protein units is accomplished via a water-network akin to a string telephone. This communication is aligned with a ‘breathing’ motion, that is the expansion and contraction of the protein.

This time-lapse sequence of structures reveals dynamic motions as a fundamental element in the molecular foundations of biology.

Im Focus: Milestones on the Way to the Nuclear Clock

Two research teams have succeeded simultaneously in measuring the long-sought Thorium nuclear transition, which enables extremely precise nuclear clocks. TU Wien (Vienna) is part of both teams.

If you want to build the most accurate clock in the world, you need something that "ticks" very fast and extremely precise. In an atomic clock, electrons are...

Im Focus: Graphene sets the stage for the next generation of THz astronomy detectors

Researchers from Chalmers University of Technology have demonstrated a detector made from graphene that could revolutionize the sensors used in next-generation space telescopes. The findings were recently published in the scientific journal Nature Astronomy.

Beyond superconductors, there are few materials that can fulfill the requirements needed for making ultra-sensitive and fast terahertz (THz) detectors for...

Im Focus: Physicists from Stuttgart prove the existence of a supersolid state of matte

A supersolid is a state of matter that can be described in simplified terms as being solid and liquid at the same time. In recent years, extensive efforts have been devoted to the detection of this exotic quantum matter. A research team led by Tilman Pfau and Tim Langen at the 5th Institute of Physics of the University of Stuttgart has succeeded in proving experimentally that the long-sought supersolid state of matter exists. The researchers report their results in Nature magazine.

In our everyday lives, we are familiar with matter existing in three different states: solid, liquid, or gas. However, if matter is cooled down to extremely...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Society 5.0: putting humans at the heart of digitalisation

10.09.2019 | Event News

Interspeech 2019 conference: Alexa and Siri in Graz

04.09.2019 | Event News

AI for Laser Technology Conference: optimizing the use of lasers with artificial intelligence

29.08.2019 | Event News

 
Latest News

Too much of a good thing: overactive immune cells trigger inflammation

16.09.2019 | Life Sciences

Scientists create a nanomaterial that is both twisted and untwisted at the same time

16.09.2019 | Materials Sciences

Researchers have identified areas of the retina that change in mild Alzheimer's disease

16.09.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>