Batteryless activity monitor

1. An apparatus comprising:

at least one base layer arranged as a substrate for printed electronics;

an energy harvester printed on the at least one base layer and arranged to transform kinetic energy into electric energy;

an energy storage printed on the at least one base layer, coupled to the energy harvester, and arranged to store the electric energy;

a display element printed on the at least one base layer, coupled to the energy storage, and arranged to provide a display view to a user of the apparatus; and

a control circuitry configured to determine the amount of the electric energy stored in the energy storage and to control the display element to update the display view according to the amount of the electric energy.

2. The apparatus of claim 1 , wherein the energy harvester is the only energy source of the apparatus.

3. The apparatus of claim 1 , wherein the electric energy transformed by the energy harvester is used as an energy source for providing said display element and the control circuitry with operating voltage and as a motion measurement signal measuring accumulated motion of the apparatus.

4. The apparatus of claim 3 , wherein the apparatus is an activity monitoring apparatus, and wherein the control circuitry is configured to control the display element to output an indicator indicating the measured accumulated motion to a user of the apparatus.

5. The apparatus of claim 1 , wherein the control circuitry comprises a comparator configured to compare the amount of electric energy stored in the energy storage with a determined threshold and, upon the amount of electric energy stored in the energy storage exceeds the determined threshold, to discharge at least some of the electric energy to the display element to change the contents of the display element.

6. The apparatus of claim 5 , wherein the comparator comprises a Zener diode.

7. The apparatus of claim 1 , wherein the control circuitry comprises at least one memristor, wherein the state of the memristor characterizes the amount of the electric energy.

8. The apparatus of claim 1 , wherein the display element consumes energy only when updating the display view.

9. The apparatus of claim 8 , wherein the display element comprises an electronic ink display.

10. The apparatus of claim 1 , wherein the apparatus comprises a sticker.

11. The apparatus of claim 1 , wherein the base layer is made of at least one of plastic and textile.

12. The apparatus of receding claim 1 , wherein the apparatus is a disposable product.

13. A method for manufacturing an apparatus, comprising:

causing printing of an energy harvester on at least one base layer serving as a substrate for printed electronics, wherein the energy harvester is arranged to transform kinetic energy into electric energy;

causing printing of an energy storage on the at least one base layer and coupling of the energy storage to the energy harvester such that the energy storage stores the electric energy harvested by the energy harvester;

causing printing of a display element on the at least one base layer and coupling of the display element to the energy storage, wherein the display element is arranged to provide a display view to a user of the apparatus; and

causing printing of a control circuitry on the at least one base layer, wherein the control circuitry is printed such that it is capable of determining that a sufficient amount of energy is stored in the energy storage by the energy harvester and, as a consequence, control the display element to update the display view.

14. A computer program product embodied on a non-transitory distribution medium readable by a computer and comprising program instructions which, when executed by the computer, perform operations comprising:

causing printing of an energy harvester on at least one base layer serving as a substrate for printed electronics, wherein the energy harvester is arranged to transform kinetic energy into electric energy;

causing printing of an energy storage on the at least one base layer and coupling of the energy storage to the energy harvester such that the energy storage stores the electric energy harvested by the energy harvester;

causing printing of a display element on the at least one base layer and coupling of the display element to the energy storage, wherein the display element is arranged to provide a display view to a user of the apparatus; and

causing printing of a control circuitry on the at least one base layer, wherein the control circuitry is printed such that it is capable of determining that a sufficient amount of energy is stored in the energy storage by the energy harvester and, as a consequence, control the display element to update the display view.