Abstract: Systems and methods for monitoring cutting forces in a peripheral end milling process are disclosed. The systems and methods comprise a sensor module that integrates a thin-film Polyvinylidene Fluoride (PVDF) piezoelectric strain sensor and an in situ data logging platform for monitoring such cutting forces. The module, which may be mounted on the tool shank, measures the dynamic strain(s) produced in the tool and logs the data into an on-board card for later retrieval. The close proximity between the signal source and the PVDF sensor(s) minimizes the attenuation and distortion of the signal along the transmitting path and provides high-fidelity signals. Further, the module facilitates the employment of a first-principles model based on Euler-Bernoulli beam theory and the constitutive equations of the piezoelectric sensor material to relate the in situ-measured PVDF sensor signals to the feed and transverse forces acting on the tool.