Download A wearable system of micromachined piezoelectric cantilevers

A wearable system of micromachined piezoelectric cantilevers coupled
to a rotational oscillating mass for on-body energy harvesting
ABSTRACT
Over the past two decades, there has been significant interest In converting
mechanical energy from human motion Into electrical energy. This electrical energy can then be
used to Recharge batteries in electronic devices or directly power small scale, Low-power
circuits.
A number of commercial devices use human power to produce Electricity such
as hand-crank generators (for powering Flashlights, radios, and recharging mobile devices), and
pedal Generators (that can be used to power larger electrical devices typically generating
between 100 and 1000Wand can be as high As 1000 W). However, these generators require
concentrated human Effort for long periods of time, which might preclude the User from doing
other tasks. It is desirable to scavenge or harvest Energy from human movement, while the user
is performing His/her everyday activities.
Some of the earliest work to harvest energy from human gait Dates back almost
250 years and include the self-winding Watch and closely related modern electromechanical (or
so called Electrical) self-winding watches, and various shoe mounted Foot cranks Driven by the
potential to power small, portable electronic devices, the first work in self-powered electrical
Energy harvesting included electromagnetic vibration in A device carried on the hip, and
piezoelectric strain energy Harvesting by a device mounted in the heel of a shoe.
This Initial work has lead to substantial interest in gait powered energy
Harvesting. The mechanical energy generated from the movement of the human movement into
electrical energy. The output of accelerometer and piezo plate is given to the ADC for analog to
digital conversion and then to microcontroller in order to monitor the value of energy generated.
The outputs of transducers are also given to boost controller. The obtained energy is boosted up
using Boost Controller and given to DC-DC converter. The output of the DC-DC converter is
stored in a storage device. The stored energy is inverted to AC voltage and is given to the relay
and utilized for other purposes for lighting lamps for example. The voltage control is provided by
the microcontroller.
EXISTING SYSTEM
Energy harvesting sources including solar, wind and thermal each with a
different optimal size. They either waste much available energy due to impedance mismatch, or
they require active digital control that incurs overhead, or they work with only one specific type
of source. No more research on the vibration domain.
DISADVANTAGES
1) Construction cost is high in normal energy harvesting like wind, solar.
2) Not will be compact.
3) More storage device required.
PROPOSED SYSTEM
This paper has investigated the optimal power that can be extracted from human gait
over a wide speed range using electromechanical vibration conversion from human movement.
Driven by the potential to power small portable electronic devices, more recent
research in energy harvesting from gait has focused on 1) increasing the power output 2) energy
harvesting from the motion of backpacks during walking, and 3) minimizing energy expenditure
by controlling the breaking force.
ADVANTAGES
Good output power.
Easy Method.
Portable Technologies.
Boost level increased.
Should be trustable one.
HARDWARE REQUIREMENTS

MICROCONTROLLER – Collect the sensors value and produce PWM

ADC- converts the sensors value in 8 bit digital output to UC.

ACCELEROMETER - produce movements corresponding analog values

Piezo electric plate- convert vibration into electricity

DC-DC BOOSTER – boost up the input voltage depends upon pwm

super capacitor- make uniform charging into the battery

battery- used for the energy storage purpose

relay- provide automatic switching operation

inverter- convert the dc voltage into ac voltage for rut the load

LCD- for monitoring purpose
SOFTWARE REQUIREMENTS

KEIL CROSS COMPILER

PROTEUS SOFTWARE