propagated further and can be harnessed to generate electricity spring coil used in the electromagnetic configuration setup acts as a mechanical energy storage device the feedback of the vibrations that happen between the electromagnetic and piezoelectric systems when the spring coil undergoes extension or compression leads to the efficient generation of electricity the book u201c energy harvesting technologies u201d by shashank priya and daniel j inman describes efficient methods of energy harvesting in a multimodal environment as depicted in fig1 energy generated from vibration of an object moving on a solid surface is converted to electricity using an electromagnetic and piezoelectric framework the electrical circuit interfacing with this framework can be designed to be a combination of but not limited to one or more of resistors inductors capacitors semiconductors etc for maximum efficiency fig2 shows the framework in greater detail electromagnetic and piezoelectric mechanisms contribute both individually and mutually to generate electric output when mechanical stress is applied the electromagnetic effect is created in the framework using electromagnetic induction principles electromagnetic induction was discovered in 1831 by michael faraday fig3 depicts electromagnetic induction michael faraday stated that the electromotive force emf produced around a closed path is proportional to the rate of change of the magnetic flux through any surface bounded by that path in practice this means that an electric current will be induced in any closed circuit when the magnetic flux through a surface bounded by the conductor changes this applies whether the field itself changes in strength or the conductor is moved through it for the special case of a coil of wire composed of n loops with the same area the equation becomes the direction of induced current is always such that it produces a magnetic field that opposes to a greater or lesser extent the.