Fig. 2. Characteristics of the porous PZT and PZT–PDMS composites manufactured by freeze casting. (a–d) Images of freeze cast porous PZT ceramics with different geometric patterns before sintering, e.g. square, round, rectangular, arbitrary showing the capability of producing arbitrary structures. (e) SEM image of a porous PZT ceramic with porosity of 50 vol%, which shows highly aligned unidirectional lamellar microstructure. (f) SEM cross section of the porous PZT structure that shows both dense, cellular zones and lamellar regions. (g) Flexible PZT sensor encapsulated in PDMS. (h) Flexible pressure sensor with painted silver electrodes encapsulated in PDMS. (i and j) SEM image of lamellar PZT structure without and with PDMS, respectively.
