Energy Harvesting

The technology of security systems has changed a lot in recent years, in the mobile as well as in the immobile sector: from mechanical lock and key systems to first transponders with wireless support and up to current mechatronic systems. These systems are equipped with a radio-based transmission technology for authentication and an automated locking system driven by actuators. Recently, the focus shifts away from pure security technoology towards considerations how these operating modes can be implemented in an energy efficient way.

Energy efficiency in mobile applications is beneficial for the range of weight-optimized electrical cars. For the immobile use in buildings longer maintenance intervals  for battery-powered transponder technologies and energy-sufficient system solutions are possible. Crucial to the successful implementation of such systems are the conversion of energy generated by disposable environmental energy flows (energy harvesting) on the one hand and a mostly efficient use of the generated or converted energy (power management) on the other hand. This requires new solutions for the challenges of envergy conversion and supply, the secure wireless authentication and communication as well as energy-efficient implementation of locking devices and other required technical characteristics.

Within our research activities, both aspects should be observed in mobile and immobile security systems. Developed approaches shall be demonstrated with common industrial partners in the field of security technologies.

The illustration above shows a first approach consisting of a lock and commercial energy harvesting components, such as from flashlights. With a gear ratio of 1:50, a simple free-running as well as a three-phase generator about 100 per mWs door-handle pressure can be "harvested" currently that are stored in a battery which supplies the lock cylinder with power. 

Innovative actuator technology

Research activities of the ISS in the field of shape memory alloys will show the high application potential of this technology in mobile and immobile segments. A partner in these research activities is the FG-innovation, a company that has emerged at the Ruhr-University Bochum from the Collaborative Research Center (SFB) 459 "Shape Memory Technology".

Crucial for the realization of energy-efficient systems is the reduction of the system's energy demand. The energy demand in these classical mechatronic security systems is determined for instance by electric motors and gears (actuators) that are used, the internal friction and other loss mechanisms as well as the radio communication (cryptology) and power management (electronics). New materials - in particular shape memory alloys (SMA) - can replace easily electric motors and gears and thus revolutionize the security systems (in bolting devices). Existing solutions, however, are less energy-efficient and have other drawbacks that prevent production.

New concepts for interlocking with SMA-actuators shall overcome these technological barriers. These concepts should be determined by low-loss SM- materials (R-phase), which are available only recently and will be further developed by the cooperation partner of the ISS, the FG-Innovation.

In combination with an optimal layout and construction as well as intelligent power management large power savings can be realized.