Large-Area Power Transmission Sheet Using Printing Technologies Unveiled at IEDM
A team of engineers from the University of Tokyo presented a paper at the IEEE International Electron Devices Meeting (IEDM) in December revealing that they had successfully manufactured a large-area power transmission sheet by using printing technologies. According to the authors, the position of electronic objects on this sheet can be contactlessly sensed by electromagnetic coupling using an organic transistor active matrix. Power is selectively fed to the objects by an electromagnetic field using a plastic MEMS-switching matrix.
Ubiquitous electronics or ambient intelligence is attracting attention because of its potential to open up a new class of applications. The paper reports the first implementation of a large-area wireless power transmission system using organic transistors and MEMS switches. The system realizes a low-cost sheet-type wireless power source of more than several watts. This is the first step toward building infrastructure for ubiquitous electronics where multiple electronic objects are scattered over desks, floors, walls, and ceilings and need to be powered. The proposed wireless power transmission sheet may directly drive electronic objects and/or charge a rechargeable battery in the objects without a connector, thereby providing an easy-to-use and reliable power source.
The wireless power transmission sheet has been manufactured on a plastic film by using printing technologies. The effective power transmission area is 21 x 21cm2. The sheet contains a two-dimensional array of 8 x 8 cells comprising position-sensing and power transmission units. The position of electronic objects on the sheet can be contactlessly sensed by electromagnetic coupling using an organic transistor active matrix. Then, power is selectively fed to the objects by an electrmagnetic field using a two-dimensional array of copper coils that are driven by a printed plastic MEMS-switching matrix. Due to selective power transmission, the team claimed to have achieved a coupling efficiency of power transmission of 62.3%, and a power of 29.3W was wirelessly received. The thickness and weight of the entire sheet are 1mm and 50g, respectively.
