The interconversion between electrical and mechanical energies is pivotal to ferroelectrics to enable their applications in transducers, actuators and sensors. Ferroelectric polymers exhibit a giant electric-field-induced strain (>4.0%), markedly exceeding the actuation strain (≤1.7%) of piezoelectric ceramics and crystals. However, their normalized elastic energy densities remain orders of magnitude smaller than those of piezoelectric ceramics and crystals, severely limiting their practical applications in soft actuators. Here we report the use of electro-thermally induced ferroelectric phase transition in percolative ferroelectric polymer nanocomposites to achieve high strain performance in electric-field-driven actuation materials. We demonstrate a strain of over 8% and an output mechanical energy density of 11.3 J cm⁻³ at an electric field of 40 MV m⁻¹ in the composite, outperforming the benchmark relaxor single-crystal ferroelectrics. This approach overcomes the trade-off between mechanical modulus and electro-strains in conventional piezoelectric polymer composites and opens up an avenue for high-performance ferroelectric actuators.

电能和机械能之间的相互转换对于铁电体在传感器、执行器和传感器中的应用至关重要。铁电聚合物表现出巨大的电场诱发应变（>4.0%），明显超过压电陶瓷和晶体的驱动应变（≤1.7%）。然而，它们的归一化弹性能量密度仍然比压电陶瓷和晶体小几个数量级，严重限制了它们在软执行器中的实际应用。在这里，我们报告了在渗流铁电聚合物纳米复合材料中使用电热诱导铁电相变来实现电场驱动驱动材料的高应变性能。^{我们证明了超过 8% 的应变和 11.3 J cm -3}的输出机械能密度^{在复合材料中，在 40 MV m −1}的电场下，其性能优于基准弛豫单晶铁电体。这种方法克服了传统压电聚合物复合材料中机械模量和电应变之间的权衡，并为高性能铁电致动器开辟了一条途径。