Techwatch: The latest developments around the world

Energy storage, drone technology, and artificial vision. The pace of innovation never slows down.

artificial vision

Engineers at Georgia State University in the US have created a biomimetic artificial vision device that extends color recognition at the micro level.

Created from a vertical stacking structure, the designers hope it will one day be used to develop a camera small enough to be used by small robots.

Using van der Waals semiconductors, the stacking system provides greater control, allowing it to sense between shades of red, green and blue.

“The ultra-thinness, mechanical flexibility and chemical stability of these new semiconductor materials allow us to stack them in random orders,” says Assistant Professor Sidong Li.

“We actually introduce a 3D integration strategy as opposed to the current level microelectronics layout. The higher integration density is the main reason why our device architecture can accelerate the miniaturization of cameras.”

The high-quality color sensing provided by the device could one day be used to create bionic eyes that could be used by people with low vision.

net neural computing

Hundreds of ionic transistors make up this ionic circuit. Photo credit: Woo-Bin Jung/Harvard SEAS

Ionic computing is a new form of information processing that moves electrons through liquids rather than the solid semiconductors used by most electronics.

Inspired by the way the brain stores information, the researchers hope to use the different physical and chemical properties of ions to produce improved types of computing.

Now, John A. Paulson, College of Engineering and Applied Science, has pushed the concept forward by connecting individual ionic diodes and transistors into a more complex circuit that can be used in the basic process of neural network computing.

The system consists of ionic transistors made of concentric ring electrodes in an aqueous solution of quinone molecules, with “gates” that can be controlled by adjusting pH levels.

“While our ionic circuit cannot be as fast or accurate as a digital microprocessor, doubling the electrochemical array in water is magical in itself, and has the potential to deliver energy efficiently,” says electrical engineer Professor Donhee Ham.

Cooperative drones

Two drones working in tandem built this two-meter tower out of foam. Image credit: University College London

A collaboration between Imperial College London and EMBA, the Swiss Federal Laboratories for Materials Science and Technology, is using a team of drones to build the structures.

Inspired by bees and wasps, the system is called Aerial Additive Manufacturing and includes “BuilDrones,” which deposit materials, and “ScanDrones,” which maintain quality control.

“We have demonstrated the concept that drones can operate both autonomously and in tandem to build and repair buildings, at least in the laboratory,” says Professor Mirko Kovac. “This scalable solution can aid construction and repair in hard-to-reach areas, such as high-rise buildings.”

To test the system, drones were used to build a two-meter cylinder using a cement-like mixture made of polyurethane-based foam.

By evaluating the structure in real time and adjusting to specifications, the drones have achieved an accuracy of five millimeters.

The system uses a framework for 3D printing and trajectory planning, which allows drones to adapt to construction needs as the structure takes shape.

printed energy storage

The 3D-printed solid polymer electrolyte can be used as an energy storage device. Image credit: Dr. Nathaniel Corrigan

A team from the University of New South Wales has developed a 3D printing process that can create small, intricately detailed energy storage devices.

The solid polymer electrolyte (SPE) used in the process is strong and highly conductive, allowing it to be produced with sophisticated geometries without losing the properties that make it useful.

Consisting of conductive channels of ions on a nanoscale embedded in a rigid, crosslinked polymer matrix, the material can be produced inexpensively and may one day find use in medical devices.

“Another benefit of this SPE in energy storage devices is the fact that it increases cycle stability—that is, the number of charge-discharge cycles until its capacity is reduced to a certain amount,” says Dr. Nathaniel Corrigan.

“This material is very stable and has the ability to charge and discharge over thousands of cycles. After 3,000 cycles, there was only a 10 percent drop.”

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