Smart Seat

Smart Seat: When a person seats on a seat, certain amount of pressure is applied on it. If we install certain amount of piezoelectric sensor in a seat. With the help of pressure, we can generate voltage. Piezoelectric sensor is a device that uses the piezoelectric effect, to measure changes in pressure, acceleration, temperature, strain, or force by converting them to an electrical charge. Using the sensor under the seat the pressure generated by a person seated on a chair can be sensed by sensor and generate electricity. Mainly piezoelectric material that can generate a voltage proportional to the stress applied upon it. This paper is based around this process. There will be springs attached under the seat also. When pressure is applied on the spring there will be equal pressure applied on a sensor which is attached in the bottom of every spring. With this we can generate a considerable amount of voltage to use it in future by storing it in a rechargeable battery. If the pressure is more applied on the sensor, then we can generate more voltage through the process. Keywords: Sensor, Battery, Piezoelectric, Seat, pressure.

An overview on the art of piezosurgery in the maxillofacial practice

Introduction: Piezosurgery is an emerging boom in the field of maxillofacial surgery for precise, safe and effective osteotomies sparing the adjacent vital structures compared to conventional surgery. Corpus: It works on the principle of piezoelectric effect in which crystals in the piezoelectric substances get deformed on the application of an electric field. Various studies gave the evidence of improved wound healing and bone formation compared to conventional approaches. The soft tissue sparing capability with improved patient comfort and decreased blood loss gave the utmost importance for this surgical technique in the present as well as future world of surgery. Conclusion: Piezosurgery has emerging as a promising surgical modality with a wide range of clinical applications throughout the whole field of surgery.

Piezoelectricity in hafnia

Because of its compatibility with semiconductor-based technologies, hafnia (HfO2) is today’s most promising ferroelectric material for applications in electronics. Yet, knowledge on the ferroic and electromechanical response properties of this all-important compound is still lacking. Interestingly, HfO2 has recently been predicted to display a negative longitudinal piezoelectric effect, which sets it apart from classic ferroelectrics (e.g., perovskite oxides like PbTiO3) and is reminiscent of the behavior of some organic compounds. The present work corroborates this behavior, by first-principles calculations and an experimental investigation of HfO2 thin films using piezoresponse force microscopy. Further, the simulations show how the chemical coordination of the active oxygen atoms is responsible for the negative longitudinal piezoelectric effect. Building on these insights, it is predicted that, by controlling the environment of such active oxygens (e.g., by means of an epitaxial strain), it is possible to change the sign of the piezoelectric response of the material.

Design and simulation of the compact MEMS energy harvester based on aluminium nitride

A device for converting the energy of mechanical vibrations to electricity by the piezoelectric effect is presented. A main part of the transducer is a multilayer cantilever with the inertial mass at the tip. A piezoelectric layer is made of 0.5 μm thick aluminum nitride. A feature of the device is the compact lateral size of about 1 mm, which is 10 times smaller in comparison with conventional harvesters. The device is fully compatible with microelectromechanical systems (MEMS) technology. The cantilever has a natural frequency of 45-160 Hz, depending on the size and inertial mass. The transducer generates the output voltage of 0.35 V, which is high enough for rectifying by the diode bridge. The output power of 2.7 nW is relatively low due to the small size. Nevertheless, the figure of merit is higher than that for conventional AlN-based energy harvesters.