Piezoelectric Energy Harvesting Thesis Writing

Recently, one-dimensional piezoelectric nanostructures such as nanowires of zinc oxide (ZnO) and gallium nitride (GaN) has gained a lot of attention due to their combined piezoelectric and semiconducting properties.

ON THE POSSIBLE ORIGIN, PROPAGATION AND DETECTABILITY OF ELECTROMAGNETIC PRECURSORS OF EARTHQUAKES

Another project in Japan attempts to fully utilize the power of human movement. Rubber sheeting floor tiles embedded in front of ticket turnstiles contain piezoelectric mats, putting the 400,000 people that pass through Tokyo Station to good use. The same concept at the Shibuya Station, also in Tokyo, allows its patrons to contribute to the collection of energy; Soundpower Corp has installed a "Power Generation Floor" in the station and on an average weekday, 2.4 million passengers step over this floor. "'An average person, weighing 60 kg, will generate only 0.1 watt in the single second required to take two steps across the tile,' said Yoshiaki Takuya, a planner with Soundpower Corp. 'But when they are covering a large area of floor space and thousands of people are stepping or jumping on them, then we can generate significant amounts of power.' Stored in capacitors, the power can be channeled to energy-hungry parts of the station, he said, including the electrical lighting system and the ticket gates." [4]


Liste de sujets de thèses /List of PhD topics

Just a two page paper about piezoelectricity. A background about the piezo what it is and how it works. (We’re applying the piezo in the bridge.)

Currently, smaller projects have been exploring new applications for piezoelectric energy. Numerous piezoelectricity nightclubs in Europe have sprung up in recent years, advertising their use of piezoelectricity-charged batteries to power their establishments. There are also efforts to create mobile energy sources with piezoelectric fabrics, allowing for energy to be collected from more than just footsteps-- including heartbeats, ambient noises, and airflow. [2] Furthermore, researchers are experimenting in harvesting piezoelectricity for bigger projects and could even turn ordinary highways and roadways into power stations. [2]


Electronics and TeleCommunication (ECE) Seminar Topics

The most frequently used detector crystal is alpha quartz. These crystals are most suitable for piezoelectric application because they are insoluble in water and resistant to high temperatures. Alpha quartz crystals can be resistant to temperatures up to 579°C with no loss of piezoelectric properties. The resonant frequency of quartz crystal depends on the physical dimensions of the quartz plate and the thickness of the electrode deposited. AT and BT-cut crystals are most useful as piezoelectric detectors. These cuts refer to the orientation of the plate with respect to the crystal structure. The AT-cut crystal is the most stable, with a temperature coefficient of 1 ppm per degree centigrade over a temperature range of 10°C to 50°C. The crystals usually take the form of discs, squares, and rectangles.

All crystals in this investigation were general-purpose 10 MHz AT-cut quartz crystals with an electrode coating deposited on each side using sputtering method. The crystal was mounted on a holder with stainless steel with leads. A silver composite was used to connect the electrode to wire. The crystals were 14 mm in diameter, and the electrodes on both sides of the crystal were 8 mm in diameter. The crystals were mounted on size HC6/u holders. shows the schematic diagram of the fabricated crystal attached to the base.

is a block diagram of the apparatus used for the biosensor experiment. The piezoelectric quartz crystal was driven by a low-frequency transistor oscillator, powered by a 1-30 V d.c. regulator power supply and set at 9 V d.c. The frequency of the vibrating crystal was monitored by a Protek multifunction frequency counter. The crystal mounted on its holder was connected to the oscillator circuit and the frequency counter was connected to the oscillator device. After each step in the coating process-first with the various metal depositions and then with the biomolecular analytes-the frequency reading was recorded.

Immunosensing

The crystal electrodes were first modified with a 5 ml coating of protein A for better adhesion of the antibodies to the surface of the transducer. Protein A is a polypeptide isolated from that binds specifically to the immunoglobulin molecules, especially IgG antibodies, without interacting at the antigen site. This property permits the formation of tertiary complexes consisting of protein A, antibody, and antigen. Prior to modification, the electrodes were anodically oxidized at constant current in 0.5 M NaOH. They were then cleaned in 0.5 M HCl and 0.5 M HCrO. They were dried in an incubator for one hour, and the antibody (IgG) coating was then applied to the protein A coating. Using a pipette, 10 ml of antibody was applied on both sides of the crystal. After another hour of drying, 10 ml of antigens were coated onto the crystal, and they were methodically dried again. After each step, the frequency of the crystal was recorded, and the crystal was washed as a precaution against non-specific binding.

Control crystals and experimental crystals were coated with antibodies. The former were coated with an irrelevant antibody (HBV-honey bee antibody), one specific for an antigen not present in the solution containing the analyte. The experimental sample was coated with antibody (M. tuberculosis) specific for binding to the antigen. Both were exposed to the solution containing the analyte. Then the difference in frequency change between the control and experimental crystals were compared, reflecting the immunologically specific binding of analyte. This procedure was carried out first with crystal with gold substrate, and then using crystals coated with magnetic materials. A magnetic field was induced during the investigation of the latter. The nature of the binding of antigen to antibody to the surface of the transducer is shown in . The protein helps the antibody to bind to the electrode and the antigen in gaseous state binds to specific antibody.

Pulse transformer [Encyclopedia Magnetica]

These results are preliminary. More analysis is needed to shed more light on the optimum binding characteristics of the antigen and antibody to the piezoelectric transducer.