13-11-2012, 04:45 PM
A large-area flexible wireless power transmission sheet using printed plastic MEMS switches and organic field-effect transistors
![Adobe Acrobat PDF .pdf](https://seminarproject.net/images/attachtypes/pdf.gif)
Abstract
We have successfully manufactured a large-area
power transmission sheet by using printing technologies.
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.
Introduction
Ubiquitous electronics or ambient intelligence is
attracting attention because of its potential to open up a
new class of applications. This paper reports the first
implementation of a large-area wireless power
transmission system (Fig. 1) using organic transistors
(1-9) 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. These objects may
be mobile or located in the dark and therefore solar cells
cannot be used to power them. On the other hand, the
periodic replacement of the primary batteries could be
tedious since there may be too many objects. 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.
Device characteristics
The contactless position-sensing sheet (Fig. 4): The
pentacene transistors in DC characterization exhibit
mobility of 1 cm2/Vs and an on/off ratio of 105. A
voltage of ±10 V at a resonance frequency (2.95 MHz) is
applied to the position-sensing cells. The on/off ratio of
the transistors at 2.95 MHz exceeds 500. When the
distance between the position-sensing coil and the
receiver coil reduces, the change in output voltage
increases and reaches 91%.