Abstract This paper presents design and simulation of polyvinylidenefluoride (PVDF) cantilever. However, poly(vinylidenefluoride-trifluroethylene) P(VDF-TrFE) has better piezoelectric properties than PVDF. In view of this, piezoelectric â-phase of P(VDF-TrFE) which is essential for energy harvesting has been investigated. The spin coated films of P(VDF-TrFE) were heat-treated at various temperatures to realize â-phase. The results indicate the presence of â-phase in films heat-treated at 115oC for one hour confirmed using high resolution X-ray diffraction technique. Through Solidworks-simulation software, we show that for a unimorph cantilever with design dimensions 45mm x 30 mm x 3.5 mm and 12mm thick proof mass a fundamental vibrational frequency of 50 Hz (which is required for body energy harvesting) is achievable. 1. Introduction There has been an increase in wearable devices such as external wearable medical devices, mobile phones, wireless electronic devices etc. due to advancement in wireless technology and low power electronics. Major sources of energy that can be used are environmental vibrations and motion of biological systems; these sources are ideal for piezoelectric materials which have the ability to convert mechanical energy into electrical energy with high conversion efficiency [1]. The concept of utilizing piezoelectric materials for energy generation has been studied greatly over past decades [2, 3]. One ambient vibration energy source is human movement [4], with energy available in breathing, blood pressure/pulse and body movements. Approximately 60–70W of power is consumed during walking and a piezoelectric material in a shoe with a conversion efficiency of 12.5% could produce 8.4W of power. On the other hand, intelligent clothing with flexible piezoelectric materials integrated into fabrics such as gloves [5], may be able to convert a portion of mechanical energy associated with daily activities into electric energy. Converted electrical energy can be used to charge wearable mediums giving greater battery life, or in an ideal scenario, a self-maintaining power supply. Wearable devices will undoubtedly multiply in the years to come due to a constant decrease in size and power requirements of electronic systems. Smart systems such as wireless sensing nodes etc., can be powered by the energy from the ambient motion of the body, eliminating the need for periodic battery replacements [6, 7]. The power generation in the harvester can be realized by exploiting electromagnetic, electrostatic or piezoelectric effect. The required voltages are generated directly in piezoelectric and electromagnetic conversion mechanisms, while in electrostatic generators, the conversion process is initiated by a separate voltage source. While electromagnetic generators are suitable for generating energy at high frequencies, piezoelectric harvesters can outperform the electromagnetic generators at low frequencies [8]. In Addition, the volume occupied by the piezoelectric generators is smaller than that of the electromagnetic harvesters for a given normalized power density [9]. Hence piezoelectric conversion is a better mechanism to harvest energy at frequencies below 100 Hz. However, there is a limited choice of piezoelectric materials suitable for low frequency resonator designs [10]. PVDF is an attractive piezoelectric material for harvesters owing to its low elastic stiffness allowing the design of resonators with the fundamental mode of vibration below 100Hz Recently it has been reported that Poly(vinylidenefluoride-co- trifluoroethylene P(VDF-TrFE) has better piezoelectric properties than PVDF. One of the most efficient configurations for a body energy harvesting device is a cantilever with low natural frequency. A piezoelectric harvester with the cantilever configuration having a single layer of piezoelectric material is called a unimorph and that with two layers is called a bimorph [11]. The energy harvester so developed could be integrated with wireless sensor node for in-vitro applications such as monitoring patient health like heartbeat. Energy harvesters have wide ranging potential such as in-vivo applications for powering pacemakers etc. The in-vivo applications though are challenging due to the biocompatibility issues of the energy harvester. Nevertheless, the first set of in-vitro applications appear to be realistic. In this paper, simulation, design and identification of PVDF-TrFE in its piezoelectric phase for the fabrication of unimorph cantilever has been presented. Simulation and fabrication considerations of P(VDF-TrFE) cantilevers 1 2 3 1 1 1 4 5 K.R. Rashmi , Swathi Rai , Rathishchandra R. Gatti , A. Jayarama , Navin Bappalige , Niraj Joshi , R.Pinto , S.P. Duttagupta 1 Physics Dept., Sahyadri College of Engineering & Management, Adyar, Mangalore-575007 2 E & C Dept., Sahyadri College of Engineering & Management, Adyar, Mangalore-575007 3 Mechanical Engg. Dept., Sahyadri College of Engineering & Management, Adyar, Mangalore-575007 4 CENT, Sahyadri College of Engineering & Management, Adyar, Mangalore-575007 5 Electrical Engineering Department, IIT Bombay, Mumbai-400050 Email: rashmi.kr.988@gmail.com, Mob.: +91-8105284348 Research Paper 8 SAHYADRI International Journal of Research | Vol 1 | Issue 1 | December 2015