WELCOME

Done by,

LIJINRAJ.T.VGuided by,

Muhzina M H

Ultrasonic energy harvester

CONTENTS

INTRODUCTION DESIGN FABRICATION EXPERIMENTAL RESULTS CONCLUSION REFERENCES

INTRODUCTION NEED OF ENERGY HARVESTERS

EXISTING HARVESTERS

DRAWBACKS

ULTRASONIC ENERGY HARVESTER

TWO METHODS.

USING MEMS.

USING PIEZOELECTRIC CANTILEVER.

ULTRASONIC ENERGY HARVESTER USING MEMS ULTRA SONIC

TRANSDUCERS

MEMS CHIP

STORAGE DEVICES

BLOCK DIAGRAM

VOLTAGE SOURCE

ULTRASONIC TRANSDUCER

MEMSHARVESTER

RECTIFIER & STORAGE DEVICES

ULTRASONIC TRANSDUCER A SQ -40T ULTRASONIC

TRANSDUCER WAS USED.

IT TRANSMITS ULTRASONIC WAVES.

IT HAS A RESONANCE FREQUENCY OF 40 KHZ.

DRIVEN BY A 10Vpp AC SIGNAL.

MEMS

MEMS(Micro Electro Mechanical System).

CONSISTS OF MICRO ACTUATORS

MICRO SENSORS,MICROELECTRONICS

SIZE IS IN µm RANGE.

DESIGN

3-D VIEW OF MEMS MECHANISM

A 2 DOF MOTION MECHANISM .

VIBRATION ENERGY. SEISMIC MASS MOVES. CHANGES THE

CAPACITANCE OF THE X&Y FRAMES.

CONITRIBUTE THE CHARGING OF THE LOAD.

MOTION MECHANISM TO HARVEST VIBRATION ENERGY TO A PLANE

TWO MODES.

TWO RESONANCE FREQUENCIES.

MECHANICAL COUPLING IN THE COMBS FROM ONE MODE TO ANOTHER IS LESS THAN 2%.

VIBRATION IN Z-DIRECTION CAN BE IGNORED.

RESONANCE FREQUENCY DEPENDS ON THE STIFFNESS OF THE BEAMS AND MASS,

MECHANICAL STRUCTURE DESIGN SHOWING THE MOVEMENT ALONG THE X-AXIS

MECHANICAL STRUCTURE DESIGN SHOWING THE MOVEMENT ALONG THE Y-AXIS

DESIGN PARAMETERS FOR 2-DOF ENERGY HARVESTER

FABRICATIONMEMS FOUNDRY PROCESS

SURFACE METALPADS ARE

PATTERNED FOR OHMIC CONTACT

DRIE IS PERFORMED FROM THE FRONT SIDE OF THE WAFER

A PROTECTIVE POLYMIDE LAYER IS APPLIED TO THE FRONT SIDE

A DEEP TRENCH UNDERNEATH

THE MOVABLE STRUCTURES

IS CREATED

THE EXPOSED BURIED OXIDE

IS REMOVED USING A WET HF

ETCH

THE POLYMIDE COAT

IS REMOVED BY OXYGEN

PLASMA

SEM IMAGE OF THE FABRICATED ENERGY HARVESTER

PHOTOGRAPH OF THE PACKAGED DEVICE

ENERGY HARVESTING CIRCUIT DIAGRAM

ULTRASONIC ENERGY IS CONVERTED INTO ELECTRICAL ENERGY.

A RECTIFYING CIRCUIT IS USED.

DIODES (1N5711).

CAPACITOR CHARGED(1µF).

ULTRASONIC TRANSDUCER & PACKAGED MEMS CHIP

MAGNITUDE CURVES OF THE OUTPUT VOLTAGE V/S FREQUENCY

COMPARISON BETWEEN EXPERIMENTAL RESULTS &STIMULATION

RESULTS

USING PIEZOELECTRIC CANTILEVER

MEMS V/S PIEZOELECTRIC CANTILEVER

ADVANTAGES

SMALL SIZE.

BETTER SENSITIVITY.

COST EFFECTIVE.

LESS HARM TO PATIENT.

APPLICATIONS

A BETTER APPLICATION IS IN POWERING THE IMPLANTABLE BIOSENSORS.

CONCLUSION THESE CAN EXTRACT ULTRASONIC ENERGY FROM

ALL DIRECTIONS IN THE DEVICE PLANE.

INCREASES EFFICIENCY OF THE ENERGY SCAVENGING.

A POWER LEVEL OF 21.4nw CAN BE OBTAINED.

BETTER SENSITIVITY.

REFERENCES

Yong Zhu, S. O. Reza Moheimani, Mehmet Rasit Yuce, “A 2-DOF MEMS Ultrasonic Energy Harvester”, IEEE SENSORS JOURNAL, VOL. 11, NO. 1, JANUARY 2011

WWW.WIKIPEDIA .COM

THANKS

QUERIES???