B1500a semiconductor device analyzer

The X-ray diffraction (XRD) measurement for TiO₂/Ti was performed by using a SmartLab XRD system (Rigaku, Tokyo, Japan). The thickness of the TiO₂ on the Ti substrate was measured by using a SE-2000 spectroscopic ellipsometer (Semilab Japan, Tokyo, Japan). The EGFET in this study was assembled by using a 2N7000 N-channel enhancement-type MOSFET (ON Semiconductor, Phoenix, AZ, USA). The pH and glucose measurements of our EGFETs were performed by using an RE-1B Ag/AgCl reference electrode (ALS, Tokyo, Japan) and a B1500A semiconductor device analyzer (Keysight, Tokyo, Japan). The pH change in the PBS during measurement was monitored by using an AT-610ST titrator equipped with a C171 glass electrode (Kyoto Electronics, Kyoto, Japan). The thickness, roughness, optical absorption, and surface morphology of the SF membrane were measured by using a DektakXTS-0K1704 stylus-type step profiler (Bruker Japan, Kanagawa, Japan), an SPM9700 atomic force microscope (AFM) (Shimazu, Kyoto, Japan), an FTIR-8400S Fourier transform infrared spectrometer (FTIR) with a DRS-8000A diffuse reflector (Shimazu, Kyoto, Japan), and a VE8800 scanning electron microscope (SEM) (Keyence, Osaka, Japan), respectively.

A probe station with a semiconductor
device analyzer (B1500A Semiconductor Device Analyzer, Keysight Technologies)
was used to measure sheet resistance via the van der Pauw method.
To get high-resolution images of the PET-embedded Ag meshes, SEM (Zeiss
SIGMA VP) was employed. The total transmittance was measured over
the wavelength range of 400–800 nm using a UV–vis–(near-infrared)
NIR spectrometer with a 100 mm diameter integrating sphere (PerkinElmer
Lambda 750). The transmission values reported in our study were calculated
by excluding the effect of bare PET transmission. To achieve this,
we divided the measured transmission values by the bare PET transmission.
The EMI SE was determined using the coaxial transmission line method
with the aid of an HP 7822D Vector Network Analyzer (VNA) for signal
generation and detection. For the test, the samples 3 cm × 3
cm in size were positioned between two waveguide flanges, with the
appropriate flange chosen based on the targeted frequency range. Specifically,
we used the Pasternack WR-90 UG-135/U Square cover flange for the
8–12 GHz (X band) and the Pasternack WR-62 UG-1665/U Square
cover flange for the 12–18 GHz range (Ku band). To ensure stability
during measurement, the waveguide flanges were firmly attached using
screws and nuts.

After fabrication, the MEMS rotational structures were characterized electromechanically using a semiconductor measurement probe station along with a Keysight B1500A semiconductor device analyzer. Four source/measure units were used to provide signal input, and the probe tips were connected to the aluminum pads on the device. Start Easy EXPERT software was used to control the measurement channel current (I)/voltage (V) sweep during the experiments. To determine the displacement of the MEMS rotational structures, the thermal actuators were actuated by applying a DC voltage ranging from 1 to 2 V, with incremental steps of 0.2 V, and the experimental displacement was measured in air by processing microphotographs captured at each voltage. To ensure that the system was in a steady state, a delay of 7 s and a hold of 2 s were implemented between each voltage increment and image capture. For each trial, offset pictures taken at 0 V were used as a reference. The experimental displacement was measured by analyzing the acquired microphotographs using the GNU Image Manipulation Program (GIMP).