Power without the cord

April 2, 2012
With the aid of magnetic coupling, power can be transmitted wirelessly from a transmitter to a receiver module. The prototype with the transmitter can be attached to the belt. Credit: Fraunhofer IKTS

Cell phones and flashlights operate by battery without trouble. Yet because of the limited lifespan, battery power is not a feasible option for many applications in the fi elds of medicine or test engineering, such as implants or probes. Researchers have now developed a process that supplies these systems with power and without the power cord.

For more than 50 years, have set the rhythm for many hearts. The engineering of microelectronic implants has since advanced by leaps and bounds: they have become ever-smaller and more technologically sophisticated. The trend is moving toward miniaturized, that will take over therapeutic and diagnostic functions. For example, in the future implantable sensors will measure , blood pressure or the of tumorous tissue, transmitting via telemetry. Meanwhile, medication dosing systems and infusion pumps will be able to deliver a targeted release of pharmaceutical substances in the body, alleviating side effects in the process.

All these solutions are composed of probes, actuators, signal and electronic controls – and therein lies the problem, too: they must have a power supply. Batteries are usually ruled out because of their limited durability – after all, implants stay inside the body for years. Currently, radio wave-based (HF) and inductive systems are most commonly in use. However, these exhibit differences in efficiency based on location, position and movement and are also often limited in range. Soon, a new power transfer system should circumvent the limitations of previous methods. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Hermsdorf succeeded in wirelessly transmitting power from a portable transmitter module to a mobile generator module – the receiver. “The cylindrical shaped transfer module is so small and compact that it can be attached to a belt,” says Dr. Holger Lausch, scientist at IKTS. The transmitter provides an electric current of over 100 milliwatts and has a range of about 50 centimeters. As a result, the receiver can be placed almost anywhere in the body. “With our portable device, we can remotely supply power to implants, medication dosing systems and other medical applications without touching them – such as ingestible endoscopic capsules that migrate through the gastrointestinal tract and transmit images of the body‘s inside to the outside,” says Lausch. The generator module can be traced any time – regardless of power transfer – with respect to its position and location. So if the generator is located inside a video endoscopy capsule, the images produced can be assigned to specific intestinal regions. If it is placed inside a dosing capsule, then the active ingredient in the medication can be released in a targeted manner.

How does this new, already patented system work? In the transfer module, a rotating magnet driven by an EC motor generates a magnetic rotary field. A magnetic pellet in the receiver connects to the alternating exterior magnetic field and as a result, is set in rotation itself. The rotational movement is transformed into electricity, thus the power is produced right in the generator module. “With magnetic coupling, power can be transported through all non-magnetic materials, such as biological tissue, bones, organs, water, plastic or even a variety of metals. Moreover, the magnetic field produced has no harmful side effects on humans. It doesn‘t even heat up tissue,” says Lausch, highlighting the advantages of the system.

Because the modules available as prototypes are scalable in terms of range, size and performance capacity, they can be used for more than medical technology applications. They can also supply power wirelessly to hermetically sealed sensors – such as those inside walls or bridges. This makes them suitable for use in mechanical engineering and plant construction and in the construction industry. Other conceivable applications include the charging of power storage units and activation of electronic components.

Using a hip implant as a demonstration tool, Lausch and his team will demonstrate how their wireless transmission system functions at the Hannover Messe from April 23–27 (Hall 13, Booth C10). As used here, the technology electrically stimulates the ball-and-socket joint to stimulate the growth of cartilage and bone cells.

Explore further: Miniaturized power modules for aircraft bodies

Related Stories

Miniaturized power modules for aircraft bodies

June 14, 2011

Aircraft maintenance can be time consuming and expensive. It is much simpler if the airplane itself reports, where maintenance is required. The best solution is an approach for the sensor network, which even provides its ...

Sony develops 1.2kWh-class energy storage module

June 23, 2010

Sony today announced the development of an energy storage module using lithium-ion rechargeable batteries made with olivine-type lithium iron phosphate as the cathode material. Key features of olivine-type lithium iron phosphate ...

Recommended for you

A not-quite-random walk demystifies the algorithm

December 15, 2017

The algorithm is having a cultural moment. Originally a math and computer science term, algorithms are now used to account for everything from military drone strikes and financial market forecasts to Google search results.

US faces moment of truth on 'net neutrality'

December 14, 2017

The acrimonious battle over "net neutrality" in America comes to a head Thursday with a US agency set to vote to roll back rules enacted two years earlier aimed at preventing a "two-speed" internet.

FCC votes along party lines to end 'net neutrality' (Update)

December 14, 2017

The Federal Communications Commission repealed the Obama-era "net neutrality" rules Thursday, giving internet service providers like Verizon, Comcast and AT&T a free hand to slow or block websites and apps as they see fit ...

The wet road to fast and stable batteries

December 14, 2017

An international team of scientists—including several researchers from the U.S. Department of Energy's (DOE) Argonne National Laboratory—has discovered an anode battery material with superfast charging and stable operation ...

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.