Mobile device manufacturers are facing a looming crisis, according to recent reports: A battery crisis, that is. With manufacturers and software companies attempting to outdo one another in equipping smartphones and tablets with power-hungry features while simultaneously slimming them down, they are rapidly pushing the limits of what the standard technology — the lithium ion battery — can accomplish. See Apple’s latest iPad, which is thicker than its predecessor due to a much larger battery, necessary to accomodate the higher-quality “retina display” screen.
One solution is to develop better batteries, on which scientists are already hard at work.
But now scientists at Brookhaven National Laboratory in Long Island, NY and at Lawrence Berkeley National Laboratory in Berkeley, California, as well as colleagues across the country, have helped to pioneer an alternative method that could lead to more efficient devices: They’ve developed a means of seeing in unprecedented detail, at the nanoscale, just how an exotic class of nanomaterials known as ferroelectrics holds an electrical field.
The finding could enable dramatically smaller and yet simultaneously higher capacity digital storage devices — think even smaller hard drives, solid state drives and thumb drives capable of holding the contents of several modern top-performance computers. These devices would also consume far less power than their current equivalents.
“Properly used, ferroelectrics could ramp up memory density and store an unparalleled multiple terabytes of information on just one square inch of electronics,” said Brookhaven physicist Myung-Geun Han in a statement released on the lab’s website on Monday. “This brings us closer to engineering such devices.”
“It may have a huge impact,” said Brookhaven physicist Yimei Zhu, in a phone interview with TPM, “If the memory density is much higher, the area can be much smaller, and a device can consume much less electricity and operate at higher-speeds.”
Ferroelectricity is a property found in certain materials, first observed in 1921, that have permanent electrical polarization, that is, an either positively or negatively charged electrical charge. The charge can be reversed if another electrical field is applied. This allows scientists to toggle the materials between two states, a necessary component for storing digital information.
Brookhaven engineered its own ferroelectric materials for the study, including germanium telluride and insulating barium titanate.
Right now, most consumer electronics rely on ferromagnetic materials, a similar concept but relating to magnetic positive and negative poles. Ferromagnetics are the types of materials found commonly outside the lab, in everyday life, such as iron and nickel. But they have their storage limits, which we may be approaching.
“With ferromagnetic materials, much of it is trial and error,” added Zhu. “Manufacturers just try different materials to see which has the highest density of information storage.”
By contrast, the new method developed by Zhu and his colleagues allows them to peer into the very footprint of the electrical charge found in ferroelectric materials, understanding for the first time how small a ferroelectric particle can be and still store information.
Brookhaven published the following diagram showing their results. The small cube is a ferroelectric particle. The top images show it with an electrical field and the bottom without.
“The smallest we can see is 10 nanometers in size,” said Zhu, “That’s about 30 atoms across on one side of a 30 by 30 by 30 cube. That’s a density increase of about three orders of magnitude.”
Such a tiny particle can still hold one bit of information, the smallest unit upon which modern computers rely to save our files and perform all of their core functions, including surfing the Web.
One reason that ferroelectric devices aren’t common yet is because until now, scientists haven’t been able to visualize with nanoscopic clarity, that is, at the atomic level, just how the tightly ferroelectric particles can be packed together without interfering with each other’s charges and losing the ability to reliably store information.
But now Zhu and his colleagues have managed to do just that, using an imaging technique known as electron holography — an electron microscope that creates a hologram of atoms and subatomic particles, and, in this case, the electric fields around the ferroelectrics.
Still, Zhu declined to speculate how long it would take ferroelectrics to become prevalent in new, thinner, electronic devices.
“This kind of stuff is just the beginning,” Zhu told TPM. “Others will find out how best to use it.”
So for now, the battery crisis rages on. Zhu and his colleagues’ research was funded by the Department of Energy’s Office of Science and their findings were published in the journal Nature Materials on July 8.
