Mesp rc v2

After the film coating and sintering process, the BCZT thin films were polarized under a corona electric field (5 kV cm⁻¹) at room temperature for 30 min. To demonstrate the simplicity and ease of use of FTS method derived films, the sample was cut into 1 × 1 cm square pieces and directly paste the copper foil tape onto the surface of the BCZT film. Thus, the copper foil tape served as the top electrode and the stainless steel served as the bottom electrode, and they were welded by conductive wires. The piezoelectric performance tests were conducted by compressing the piezoelectric thin film‐based devices under a fixed frequency and force by a vibration generator. The open‐circuit voltage output was recorded by a digital oscilloscope (Rohde & Schwarz RTE1024) and the short‐circuit current was measured by a current preamplifier (Stanford Research SR570). The surface roughness and topology characterization was conducted by an atomic force microscope (Bruker Dimension Icon System). The conductive Co/Cr‐coated silicon probes (MESP‐RC‐V2, Bruker) were used in the piezoresponse force microscopy (PFM) test, with a nominal spring constant 5 N m⁻¹ and a free‐air resonance frequency of ≈150 kHz. An AC drive voltage was applied on the sample at the resonance frequency of 685 kHz in contact mode.

The scanning probe measurements
were performed using a Bruker MultiMode 8. The surface potential of
PVDF fibers (diameter ≈ 0.5 μm) was measured via frequency-modulated
KPFM. We used the conducting cantilever (MESP-RC-V2, Bruker) with
a spring constant of 5 N/m, a resonance frequency of 150 kHz, and
a cobalt-chromium (CoCr)-coated Si tip. The PVDF fibers were electrospun
on a gold-coated silicon substrate for KPFM measurements. The KPFM
measurements were carried out using sample bias. The data was inverted
(to account for the bias being applied to the sample rather than the
tip) for easier visualization.