Biopolymers such as chitosan and poly(lactic acid) (PLA) have been widely reported as piezoelectric materials based on electrical signals generated during mechanical deformation. However, their translation into reliable electromechanical devices requires unambiguous demonstration of intrinsic piezoelectric behavior, which results from molecular-level polarization changes during mechanical deformation and distinct from ionic effects. To date, there remains a gap in the literature critically assessing the origin of these signals using established piezoelectric benchmarks. This study aims to address this gap by systematically evaluating the electromechanical responses of chitosan- and PLA-based films using poly(vinylidene fluoride–trifluoroethylene) (PVDF-TrFE) as a reference piezoelectric polymer. Films were prepared by solvent-cast, and characterised using impedance spectroscopy, high voltage poling, and dynamic bending measurements. Chitosan films exhibited ionic conductivity in the order of -10-4 S/cm, linear current–electric field behavior during poling, and measurable charge output under bending (-229 pC/rad). To investigate whether this charge output is due to ion mobility or intrinsic piezoelectricity, chitosan films were neutralised by sodium hydroxide treatment. The ionic conductivity was reduced by an order of magnitude (10⁻5 S/cm), accompanied by a reduction in the charge output under bending (9 pC/rad) This demonstrates that the electromechanical response of chitosan is likely governed by mobile ions rather than dipole alignment. PLA films, although exhibiting negligible ionic conductivity (<10⁻¹¹ S/cm), similarly showed no evidence of dipole reorientation during poling due to the absence of switchable molecular dipoles. In contrast, PVDF-TrFE films exhibited negligible ionic conductivity (<10⁻¹¹ S/cm), a distinct current transition associated with dipole reorientation during poling, and a reproducible charge output under mechanical deformation (61 pC/rad), consistent with intrinsic piezoelectric behavior. The role of mobile ions was further confirmed by introducing lithium chloride into PVDF-TrFE films, which led to a markedly increased ionic conductivity (10⁻⁶ S/cm), suppression of the current transition during poling, and a substantially reduced charge output under bending (7 pC/rad). These findings indicate that charge outputs previously attributed to piezoelectricity in common biopolymers are more likely originated from ionic mechanisms.