Inspired by the dehydration and hydration of pollen grains, the drying and subsequent recovery of the microcapsules in water were studied through different drying-swelling cycles. One advantage of PHEAl-PDMS over other microcapsule wall materials is that the APCNs are soft and flexible in both the swollen and dry states. Figure shows microscopy images of the capsules before, during, and after completing four drying-wetting cycles with water. The experiment reveals that the APCN microcapsules exhibit remarkable robustness even under the high stresses developed in the drying and rehydration processes. In the fully hydrated state, the capsules had a diameter of 266 ± 11 µm (Table ). When dried, they became deflated and bowl-shaped, most likely because the inner cavity of the capsules dried up and the capsule wall bulged inwards. After incubation in water for 20 minutes, the capsules recovered to a full spherical shape of the same size as before drying (Table ). This process could be repeated at least four times. No damage to the capsules was visible after each dehydrationrehydration cycle, indicating good recovery of the swollen APCN capsules, most likely because of the elastic nature of the capsule shell. In the microscopy images, the dry capsules seem to have cracks on their surface. However, scanning electron microscopy (SEM) images (Figure and Figure ) show that they are just wrinkles generated during drying. In the SEM images, the surface of the dry capsules after each of the drying steps appears smooth without any cracks or other defects, and the bowl-shape of the deflated capsules can be clearly seen. This confirms that the capsules remained intact during the drying process and that the water inside of the capsules had left them by diffusing through the capsule wall. Confocal laser scanning microscopy (CLSM) was used to quantify the thickness of the capsule wall (Error! Reference source not found.). To this end, the capsules were fluorescently stained with Nile Red (NR) to highlight their polymeric shell. When hydrated, the capsule wall was 25 -30 µm thick.