Fig. 13. Artificial cilia based sensors: (a) SEM image of a piezoresistive sensor based cilium with the piezoresistive element in the base (image-i) designed as per the configuration B shown in the schematic Fig. 12(a). Reproduced from ref. 108 with permission from the Institute of Physics. In image-ii the sensing element is integrated within the cilium structure. Reproduced from ref. 165 with permission from Elsevier. (b) SEM images of arras of cilia with a capacitive sensor integrated in the base both in image-i and ii, reproduced from ref. 175 and 176 respectively with permission from the Institute of Physics. (c) Magnetic artificial cilia containing magnetic nanowires embedded in PDMS (image-i) and SU-8 (image-ii) for measuring flow. Image-i reproduced from ref. 180 with permission from the Royal Society of Chemistry. Image-ii reproduced from ref. 184 with permission from the Institute of Electrical and Electronics Engineers.