Introduction
Many noxious batteries are the price for todays mobile devices and wireless communication. Energy Harvesters (systems, that collect energy from their environment) and Embedded Systems, that themselfes consume extreme little energy, together can help to replace the batteries in those devices. The goal of this research project is to replace batteries by Energy Harvesters combined with Low Power technology. This takes care of our environment and saves money too. An additional advantage is, that those devices are never out of power, as long as the Energy Harvester is active and the energy storage is not empty.
Those devices are called Low Power Embedded Systems. They will replace a lot of todays battery driven devices and are able to define completely new devices, that do not exist today. Embedded System means, that all components are integrated inside the device. Low Power means, that the system itself consumes little energy. Those devices must be engineered in a completely different way. A Low Power radio thermometer, that is simply glued to the wall and then displays the room's temperature on a LCD, is a good example for such a device. A small solar panel produces the needed energy just from day light.
Not in focus, but also a valuable result of this research are devices, that need the mains, but have a stand by function, like video recorders and TV-sets. Even today it is possible to build Low Power versions, that consume only milliwatts instead of watts. Those devices need not longer be switched off completely. So they keep e.g. time and date, that are essential for video recorders.
Definitions
Low Power means here a today available technology for designing systems, that consume little power, but that can be optimized. The term Ultra Low Power is reserved for systems, that is very close to the optimum. That means, it makes no sense to search for better solutions, using the same technology.
Motivation
A state of the art embedded system consists of a microprocessor, some memory, at least one communication interface and several input/output ports. In the future, the power generation right from the system's environment is also a part in the embedded system's part list. In the application, the whole device is a very small system, that just does any useful function, e.g. controlling sensors and actuators. Those systems share three basic problems:
- Amount of needed energy
- Communication capabilities
- Computing power
In this reasearch project, those problems are faced. But they cannot be handled without respect to their mutual interference.
Challenge
It is essential for microsensor/actuator systems, that they can be placed just where nedded. That implies, that neither mains nor a communication interface, like e.g. Ethernet, may be available in the sensor's near environment. The system must be autonomous. It is not only an option! That leads to two requirements:
The environment itself must supply the system with energy. Solar panels, mechanical energy, temperature differences, biological energy and more must be used for producing electrical energy.
In most cases, the system must have a radio communication. The communication must fullfill the demands of selforganizing systems, must be (today) multimaster and must tolerate brute breakdowns due to lack of energy.
That is the reason for the Low Power approach with microwatts and even nanowatts. Usualy, such a system is "sleeping", consuming no countable amount of energy. Only a little wake up mechanism must be active to reactivate the whole system when needed. When active, the system usues the energy from a small reservoir to do its work. That can be much more energy than currently available in the environment at that time. After work, it goes to sleep mode, collecting energy in the meantime, whenever possible.
Goal
Construction of autonomous Ultra Low Power Embedded Systems for educational purposes and industry projects. Those systems contain an Energy Harvester and a storage device. They do their work without any further service.
Start
February 2003
Use of this technology
Low Power Embedded Systems are all-in-one systems, that produce energy themselfes, just do their predefined job and are able to communicate over a small distance. Therefore, they will conquer new markets, like e.g. working on rotating masses, mobile systems or in fixed arrangement over short distances. That leads us to completely new sensor types.
Vision
Development of Ultra Low Power Embedded Systems, that are very small (aim: millimeter), cheap (less than 1 Euro) and can be used in volumes to share a job. They will be just useful little helpers everyday to increase the quality of human life.
Status
All basic work is almost done.
Next steps
Know How transfer in industrial applications and new research projects.
Further information
Book "Embedded Systems"
Keywords
Smart Dust, Ambient Intelligence, Autonomous Systems, Low Power, Mobile Systems, Autarkic Systems
Existing technological results (prototypes):
1. Collection of not continously available energy from the environment with an Ultra Low Power energy converter that can be controlled by software. Various energy sources can be used.
2. Storing of this energy in Ultra Low Power technology (almost no losses)
3. Implementation of a wakeup mechanism to control sleep and active phases automatically, realized in Ultra Low Power technology
4. Low Power radio communication, based on IEEE 802.15.4
5. High Power internet web server with Low Power radio communication
6. Solar Energy Harvester, consuming only 10 Microwatts for itself
Some finished projects
- Project 1: Development of a bidirectional radio communication based on IEEE 802.15.4
- Project 2: Development of an wireless Energy Harvester using the mains without direct connection
- Project 3: Development of an self supplying sensor with radio communication
- Project 4: Energy Harvester with a solar panel working with day light and 1,8V
- Project 5: Ultra Low Power wake up circuit for Energy Harvesters
- Project 6: Ultra Low Power Energy Harvester for small amounts of kinetic energy
- Project 7: Universal Ultra Low Power Energy Harvester
- Project 8: Pocket Lab for chemestry with nanoliter pump and autotitration
- Project 9: Autarkic magnetic coupled Energy Harvester transferring data through a wall
- Project 10: Low Power Fire Protection Door with a new concept, saving 98% of energy
- Project 11: Secure electronic lock with bidirectional communication
