Step-up converter for electromagnetic vibrational energy scavenger
  This paper introduces a voltage multiplier (VM) circuit which can step up a minimum voltage of 150 mV (peak). The operation and characteristics of this converter circuit are described. The voltage multiplier circuit is also tested with micro and macro scale electromagnetic vibrational generators and the effect of the VM on the optimum load conditions of the electromagnetic generator is presented. The measured results show that 85% efficiency can be achieved from this VM circuit at a power level of 18 ?W. 
C. Saha, T. O'Donnell, J. Godsell, L. Carlioz, N. Wang, P. Mccloskey,   S. Beeby, J. Tudor, Russel Torah