Fig. 5: In situ motion detection system consisting of the ferroelectric in-memory differentiator.

a Sketch of an in situ motion detection system comprising a camera to directly capture natural events and a ferroelectric capacitor crossbar array as the in-memory differentiator to isolate motion information. b The optical image of a 40 × 40 ferroelectric capacitor crossbar array hardware. c A schematic diagram showing how pixels in the image are encoded by voltage pulses and inputted to the ferroelectric capacitor crossbar array. d–g Four typical cases of pixel alteration and the corresponding transient currents. A positive polarization reversal (positive current bulge) is obtained when the white pixel follows a black pixel (d), the polarization reversal (current bulge) is absent when the white pixel follows the same pixel as a previous pixel (e) and when the black pixel follows the same pixel as a previous pixel (f), and a negative polarization reversal (negative current hump) is obtained when the black pixel follows a white pixel (g). Yellow color highlights the current hump. The cases of (d), (e, f) and (g) are defined for white, blue, and black pixels, respectively. h–i Two adjacent frames of images. j–k The compressed and binarized images with 8 × 10 pixels. l–m The moving pixels obtain by ideal computation and experimental ferroelectric domain switching signals. n The transient current response of the ferroelectric capacitor hardware during image (k) processing. Following the rule of (d–g), the ferroelectric domain switching signals in (n) give the motion image (m). Source data are provided as a Source Data file.