pH-sensitive opening of collection chamber in the robotic pill. a) Scheme, bright field, and fluorescent images of membrane pores of the robotic pill, i) without coating, ii) filled with an pH sensitive enteric coating containing a fluorescent dye, iii) filled with fluorescent enteric coating after one-hour incubation in gastric simulant (pH 2) and, iv) filled with fluorescent enteric coating after one-hour incubation in buffer (pH 7.4). Scale bar: 75 µm. The enteric coating contains fluorescent green dye for contrast. Scale bar: 50 µm. b) Quantification of fluorescent intensity in b (n=10). c) Photographs under fluorescent light showing the comparison of absorbent-loaded robotic pills i) with coating and ii) without coating after sequential incubation in acidic pH and neutral pH solutions containing fluorescent dye solution. Scale bar: 5 mm e) Quantification of fluorescent intensity in d (n=9).