electronica 2010

Dresden, /

combined UHF transponder and sensor on a single chip
UHF transponder technology for sensor applications – radio chip and sensor in one unit.

November 9 - 12, 2010 in Munich

Joint booth of the Fraunhofer Gesellschaft, hall A5, booth 221

The Fraunhofer Institute for Photonic Microsystems IPMS carries out customer specific developments in fields of microelectronic and micro systems technology serving as a business partner that supports the transition of innovative ideas into new products. Fraunhofer IPMS develops and fabricates modern MEMS and OLED devices in its own clean room facilities. In addition to R&D services it offers ramp-up within a pilot production. With modern equipment and about 200 scientists and engineers, the range of projects and expertise covers sensor and actuator systems, microscanner, spatial light modulators, lifetronics as well as organic materials and systems.

At the electronica 2010 in Munich Fraunhofer IPMS presents:

1. LDC (Light Deflection Cube) – a 1D scanner module

Based on its competence in developing and fabrication of micro scanner devices Fraunhofer IPMS presents a 1D micro scanner module. Its modular platform approach was developed to bridge the gap between the supply of bare micro scanner dies and the final integration in the customer application. With the drastic enhancement of the short term availability of OEM-capable customized solutions the institute proofs its competence for MOEMS specific packaging, electronics development and system design. The application specific scanner system is based on a modular approach where several prefabricated components are chosen to meet our customers demands.

The complete modular platform LDC consists of:

  • A micro scanner device (selected from available devices or even customized fabricated at Fraunhofer IPMS),
  • Chip carrier with housing and front optics,
  • Scan head with miniaturized optoelectronic position sensor for deflection control,
  • Electronics for driving the micro scanner with a standard communication interface (SPI) and I/O ports and GUI software.

2. OLED-on-CMOS for optoelectric sensor technology

The possibility of monolithic integration of the light emitter, wich is commonly used for optoelectronic applications, is revealed via integration of organic-light emitting diodes (OLED) in standard CMOS integrated circuits. Thereby the often complex and cost-intensiv hybrid assembly repeals and due to this cost reduction versatile fields of applications open up. All possibilities of the recent microelectronics are available such as the use as a photodetector or for electronic processing of the received signals. The principle of OLED-on-CMOS-Integration therefore can be used for reflex-, colour- and flowsensors as well as for dimensional measurement.

The exhibits show the use of OLED-on-CMOS both for simple, nondimensional optoelectric senor technology as well as for measurement technology (triangulation) in the form of so-called bidirectional mircodisplays.

Fields of application can be all industrial sectors, where optoelectronics and optoelectronic sensor technology is used. Due to the wide freedom of design in shape and colour of the OLEDs versatile applications in measurement technology and process control are implementable.

By means of the available equipment for coating of CMOS-wafers with OLEDs and subsequent encapsulation at the Fraunhofer IPMS it is possible to offer pilot fabrication of the components optimized to customer specific requirements.

3. UHF transponder technology for sensor applications

Drugs, vaccines or banked blood are very sensitive to temperature. Therefore, doctors, pharmacists and hospitals have a refrigerator for this purpose. But, what happens during transport between the pharmaceutical supplier and the ultimate customer? In order to monitor temperatures during transport, manufacturers can rely on a new RFID technology in future: If the temperature rises unexpectedly during refrigerated transport, the intelligent chip notices the variation immediately and reports the fact to the reader. This extended RFID technology is a development of the Fraunhofer IPMS. The researchers have fitted the small radio labels with a sensor. Now this new type of transponder transmits not only data, such as batch or identifi cation numbers. They have integrated sensors which measure certain parameters: irrespective of whether it is temperature, pressure or humidity – the requested ambient parameter is permanently controlled in this way.

»We have combined the UHF transponder technology with sensor technology,« says project manager Hans-Jürgen Holland.

The UHF transponders transmit signals in a frequency range between 860 Megahertz and 2.45 Gigahertz, and have a larger transmission range than conventional RFID transponders.

But, joining a transponder with a sensor module has been a challenge to researchers so far: »The maximum energy which can be transmitted to a UHF transponder is very low,« explains Hans-Jürgen Holland.

Passive transponders do not need a current source of their own, but however they can operate only in the range of the reader. As a rule this is between two and six metres in UHF transponders.

»Given this tight energy balance, it has not been possible up to now to integrate sensory functions in addition,« explains Hans-Jürgen Holland. »After all, the sensors need current as well. But now we have managed,« says the researcher.

A micro-controller on the module ensures that the data measured by the sensor are compressed and partially processed. In this way the data volume which the transponder transmits to the reader is decreased – the energy consumption decreases as well. In addition, the reader can transmit the command to control the sensors. Thus, they are not in continuous operation. Now the researchers have developed a basic element which can be adapted to the requested applications of the customer. This module contains specifically manufactured chips suitable for series production which permit the transponder module and the sensor module to be coupled. Researchers anticipate many areas of application for the UHF transponder technology, primarily in the medical field: apart from conventional batch documentation, the tags could be used to monitor the cold chain of blood products or vaccines. But, plasters could also be provided with the transponders. Moisture and temperature provide information on the progress of wound healing. During the electronica fair, the experts will present an evaluation kit which consists of a motherboard, two antennas for UHF and MW range and the software. Thus, users can develop their individual solutions.