This paper demonstrates the significant benefits of exploiting highly aligned porosity in piezoelectric and pyroelectric materials for improved energy harvesting performance.

In this study, aligned porous lead zirconate titanate (PZT) ceramics with high pyroelectric figures-of-merit were successfully manufactured by freeze casting using water-based suspensions. The introduction of aligned pores was demonstrated to have a strong influence on the resultant porous ceramics, in terms of mechanical, dielectric, and pyroelectric properties. As the level of porosity was increased, the relative permittivity decreased, whereas the Curie temperature and dielectric loss increased. The aligned porous structure exhibited improvement in the compressive strength ranging from 19 to 35 MPa, leading to easier handling, better processability and wider applications for such type of porous material. Both types of pyroelectric harvesting figures-of-merit (F E and F 0 E ) of the PZT ceramics with a porosity level of 25-45 vol% increased in all porous ceramics, for example, from 11.41 to 12.43 pJ/m 3 / K 2 and 1.94 to 6.57 pm 3 /J, respectively, at 25°C, which were shown to be higher than the dense PZT counterpart.

We demonstrate that trimethylamine borane can exhibit desirable piezoelectric and pyroelectric properties. The material was shown to be able operate as a flexible film for both thermal sensing, thermal energy conversion and mechanical sensing with high open circuit voltages (>10 V). A piezoelectric coefficient of d33≈10–16 pC N−1, and pyroelectric coefficient of p≈25.8 μC m−2 K−1 were achieved after poling, with high pyroelectric figure of merits for sensing and harvesting, along with a relative permittivity of ϵ33σ≈ 6.3.

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We demonstrate that trimethylamine borane can exhibit desirable piezoelectric and pyroelectric properties. The material was shown to be able operate as a flexible film for both thermal sensing, thermal energy conversion and mechanical sensing with high open circuit voltages (> 10 V). A piezoelectric coefficient of d 33 % 10-16 pC N À1 , and pyroelectric coefficient of p % 25.8 mC m À2 K À1 were achieved after poling, with high pyroelectric figure of merits for sensing and harvesting, along with a relative permittivity of e s 33 %6.3.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under https://doi.