1. Click to edit Present’s Name Energy Harvesting from the environment and daily activities

2. School of Computer Science and Engineering Energy Harvesting Energy harvesting is commonly defined as the conversion of ambient energy into electrical energy. Sources of ambient energy:  Radiation (light, solar, cosmic rays, electromagnetic radiation)  Thermal  Mechanical (potential, kinetic, elastic, fluid)  Chemical (battery, fuel cell, fossil fuels, phase change)  Nuclear  Magnetic (Magnetisation, currents etc) ……

3. School of Computer Science and Engineering Kinetic Energy Harvesting (Harvesting energy from Motion) By Sara Khalifa PhD Candidate School of Computer Science and Engineering, UNSW

4. School of Computer Science and Engineering Kinetic Energy Harvesting The table below shows the amount of energy that humans produce as they go about their everyday lives:

5. School of Computer Science and Engineering Modeling Energy Harvesting from the Human Motion At its most basic, a kinetic/inertial energy harvester is a small box with a weight attached to a spring.  When the spring moves, the mechanical energy is converted into electrical energy, usually by means of piezoelectrics or MEMS.  If the spring moves with more force, or it bounces back and forth rapidly, more energy is produced.

6. School of Computer Science and Engineering Piezoelectric Energy Harvesting Model I Where The energy that can be harvested using a piezoelectric cell at time t is given by:

7. School of Computer Science and Engineering Displacement Calculation Model I (Cont’d) 1. Removing the gravitational acceleration value : 2. Calculating the velocity at time t in x, y and z directions: 3. Calculating the piezoelectric displacement in x and y direction and at time t: 4. Calculating the overall displacement

8. School of Computer Science and Engineering An Example Model I (Cont’d) Time Stampxyz 2014-09-08 13:08:040.3454824.8672797.433542 2014-09-08 13:08:040.6903644.9822397.126979 2014-09-08 13:08:040.7670054.8289586.667136 2014-09-08 13:08:040.8819664.7523176.743776 2014-09-08 13:08:040.9202864.6373576.590495 2014-09-08 13:08:040.6903644.4840767.241941 Your data will look like:

9. School of Computer Science and Engineering Results Model I (Cont’d)

10. School of Computer Science and Engineering Kinetic Energy Harvesting Model II

11. School of Computer Science and Engineering Accessing the sensor on smartphone You can record the accelerometer reading using: TYPE_ACCELEROMETER TYPE_ACCELEROMETER More information: http://developer.android.com/guide/topics/sensors/sensors_motion.html Android API allows you to define the sampling rate only in relative, symbolic way.  SENSOR_DELAY_NORMAL  SENSOR_DELAY_UI  SENSOR_DELAY_GAME  SENSOR_DELAY_FASTEST 1- Read the output of the accelerometer sensor using the fastest sampling rate. 2- Save the resulted data in an excel file including these columns: -The activity you were doing in the title. -Date and Time in the format of yyyy-MM-dd HH:mm:ss -Acceleration in x,y, and z directions. Instruction

12. School of Computer Science and Engineering References [1] Muhannad Quwaider and Subir Biswas, “Modeling Energy Harvesting Sensors using Accelerometer in Body Sensor Networks”, BODYNETS, 30 September- 2 October, 2013

13. School of Computer Science and Engineering