Piezo PVDF film can be used to convert vibration and human walking to electrical energy. This utilizes the high d31 of uniaxially oriented PVDF piezo film and the bending or length-extension can generate reasonable amount of electrical charges.
We provide both plain piezo PVDF film or piezo PVDF film with electrodes. We can help provide energy harvesting circuit that regulate the voltage output from PVDF and store them into supercapacitor (output 3-5Vdc).
Uniaxially stretched PVDF piezo film is uniquely suitable for this application when operated in d31 mode (elongation of PVDF generates electrical voltage and current). The output energy is proportional to how much PVDF film you used. You can stack PVDF film in electrically series or parallel to control the output voltage and current.
A good paper: http://www.mdpi.com/1424-8220/14/7/12497
We also offer customized design to meet your special requirement.