Figure 2: Characterization of mechanical properties and effects on animal locomotor behavior.
a, Photograph of the curvature of the body of a mouse and changes in this curvature during natural movements. The colored dots mark points on the head, neck, back, and tail of the mouse for characterizing these changes as the mouse moves in an enclosure. b, Probability distribution of tensile strains (i.e. compressing and stretching) associated with routine activities, and benchtop tests of changes in resistance of the stretchable interconnects used for the BM device platform after 10,000 cycles of stretching/compressing (black line) at 1 Hz. c, Corresponding probability distribution of bending deformations (i.e. radius of curvature), d, FEA simulations of a stretched and bent BM device. e, Photographs of a stretched and bent device. f-h, Results of motion tracking (5 min in a circular arena) of freely moving mice (surgical control), mice implanted with bilateral optical fibers (tethered), and mice implanted with BM devices (BM wireless). i, Average distance traveled over 5 minutes in the circular arena (ANOVA, Tukey's multiple comparisons test; Control vs. Tethered, P = 0.01; Tethered vs. BM Wireless, P = 0.02; Control vs. BM Wireless, P = 0.99). j, Average movement speed over 5 minutes in the circular arena (ANOVA, Tukey's multiple comparisons test; Control vs. Tethered, P = 0.02; Tethered vs. BM Wireless, P = 0.02; Control vs. BM Wireless, P = 0.99). k, Average revolutions per minute when running on a wheel over a 60 minute period (ANOVA, Tukey's multiple comparisons test; Control vs. Tethered, P < 0.0001; Tethered vs. BM Wireless, P = 0.0014; Control vs. BM Wireless, P = 0.40). All data are represented as mean +/− SEM. * P < 0.05, **P < 0.01, ****P < 0.0001, ns: not significant.