One of the latest developments in the field of piezoelectric polymers is the use of poly(-benzyl-,L-glutamate) (PBLG), a poly(amino acid) that can be poled along its -helical axis and fabricated into thermally stable piezoelectric microfibers via electrospinning. This study demonstrates a method for improving the piezoelectricity of electrospun PBLG microfibers by controlling the orientation of fibers using a method based on a concentrated electric field. The piezoelectricity is verified via customized quasi-static and dynamic measurement methods, while the correlation between fiber alignment and the piezoelectric constant, d(33), in the longitudinal mode of the electrospun PBLG fibers is investigated. When the level of alignment was varied from 50% to 90%, the piezoelectric constant increased linearly, showing a maximum d(33) of 27 pC N-1 and a maximum force sensitivity of 65 mV N-1 at peak alignment. A fabricated flexible prototype based on electrospun PBLG fibers provides a new solution for the use of PBLG fibers in wearable energy harvesters or composites based on piezoelectric polymer fibers. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46440.