Energy Harvesting from Passive Human Power

          Portable equipment's are the first evolution from fixed equipment's to make possible that some day computers are part of our everyday lives. The trends in technology allow the decrease in both size and power consumption of complex digital systems. This decrease in size and power gives rise to the concept of wearable devices in which digital systems are integrated in everyday personal belongings, like clothes, watch, glasses, etc. Power is a limiting factor in this kind of devices. Wearable computers are distributed devices in clothes and therefore the power must be distributed and supplied over the body.Human power is defined as the use of human work for energy generation to power an electronic device. One possible division is to distinguish between active and passive harvesting energy method. The active powering of electronic devices takes place when the user of the electronic product has to do a specific work in order to power the product that otherwise the user would not have done. The passive powering of electronic devices takes places when the user doesn't have to do any task different to the normal tasks associated with the product. The energy is harvested from the user's everyday actions (walking, breathing, body heat, blood pressure, finger motion). Once the power is harvested it must be stored and there are many possibilities (capacitors, rechargeable batteries, etc.)