LEDs are the light source of the future because they have a very long service life and are energy efficient. However, over time their luminosity diminishes, and color changes. In general these variations are very subtle and do not represent noticeable deterioration, but in special cases – such as in operating rooms, vehicle lighting systems, or film production - these changes may affect the environment and can be distracting. This is the reason special color sensors are used in sophisticated lighting systems to compensate for variations in color and luminosity. In conventional manufacturing of these color sensors, the filters are manufactured later in a separate process step and added to the semiconductor chip.The announcement by Fraunhofer of a new color sensor with embedded on-chip filters allows production to be completely incorporated into the CMOS process. The filters are spectrally selective elements manufactured with metallic nanostructures to regulate color and intensity of the LEDs.
Magnetic Field Sensor
The ENAS division of Fraunhofer announced a new type of spintronic field sensor with two-dimensional vector resolution for contact-free measurements of distance, speed, and angle. The novel design is based on the Giant Magnetoresistance effect (GMR). The sensor can be manufactrured using standard micro-fabrication techniques such as physical vapor deposition (PVD) and plasma etching. The sensor developed by Fraunhofer attains a very high signal-to-noise ratio, extremely short time delay (response time), very low energy consumption, and a high degree of miniaturization. Because the sensor is also bio-compatible, a main application is in the design of medical devices.
ENAS also announced a new type of generator used to drive sensor systems. This generator increases the service life of sensors systems by tenfold, resulting in a cost-effective and efficient device. When there is no external activity the generator runs in power-down mode with the lowest possible consumption of energy. If an external event occurs it is converted into an electrical signal that wakes the sensor system and ensures a full supply of energy. The total consumption of the system is no more than 1.35 µA, which is considerably less than standard systems. This means that a long service life and precise measurements are no longer mutually exclusive.