E4980a lcr meter

The TFT, capacitor, and AFE measurements were carried out in a regular laboratory environment. TFTs were characterized using an Agilent 4156C Semiconductor Parameter Analyzer. Capacitors were characterized using a Keysight E4980A LCR Meter. During the measurement of the amplifier and the notch filter, the input signals were generated using a FeelTech FY200S Dual Channel Arbitrary Function Signal Generator, and the output signals were rendered on a Tektronix TDS 2012C Oscilloscope. An Agilent 4156C was used as the power supply for the acquisition of the EMG and ECG signals. Three commercial gel electrodes were used and directly connected to the inputs of the AFE system, and the output of the AEF system was directly connected to the Tektronix Oscilloscope. The participant in the experiment shown in Figure 8 is author Runxiao Shi, who has given his consent to publish the data. The AFE testing on the skin surface does not require ethical committee approval because the experiments are only on the surface of the human body, are not invasive, and do not affect the health of the person physically or psychologically. The only participant in the experiment was Runxiao Shi, and no identifiable private signals were collected.

I–V and C–V measurements were performed with an Agilent B1500A Semiconductor Analyzer and Keysight E4980A LCR meter to confirm the initial electrical characteristics of each MIM capacitor and TFT. To determine the difference in stability of MIM capacitors, capacitance and leakage current changes were confirmed by applying − 10 V, − 20 V, and − 30 V bias stresses to the top electrode at 70 °C with 1-h intervals. For NBTS evaluation, − 10 V gate voltage was applied to the a-IGZO TFTs at 70 °C for 4000 s, and the results confirmed the changes in electrical characteristics.

The Keysight E4980A LCR meter has a seven-digit resolution and its list-scan function allows inputs of up to 201 points of frequencies (20 Hz~2 MHz), test signal levels, or offset levels for automatic measurement. E4980A also supports an automatic testing through a GPIB interface. The official website provides a sample program named E4980A Data Transfer Program (EDTP) in which the PC could read manual measurement data. The software is based on Excel macros, which use Visual Basic for Applications (VBA) programming language, connected to the PC via Virtual Instrument Software Architecture (VISA).
We have upgraded the EDTP for fully automatic multigroup testing by adding some new features: (a) fully remote control and no local operation required (including automatic switching of the display interface); (b) set voltage start value and voltage step to realize voltage scanning when the frequency scan ends; (c) set any measuring frequency point; and d) the delay setting between the measurement groups facilitates a long series of continuous testing at constant voltage and frequency. The upgraded data transfer program (E4980_DataTransfer_64bit_upgraded.xlsm) is given in the Supplementary Material.

The electrical characterizations of the OFETs were carried out on a standard probe station with a Keysight B1500A semiconductor device analyzer in ambient air. Field-effect hole mobility in saturation regime (μ_sat) and threshold voltage (V_th) were extracted via the relation I_D = −(W/2L)μ_FEC_i(V_G − V_th)², where W, L, and C_i are the channel width, channel length, and areal capacitance of the gate dielectric, respectively. The effective carrier mobility (μ_eff) was calculated by μ_eff = r × μ_sat, where r is the reliability factor defined as [38 (link)] $r={\left[\left(\sqrt{\left|I_{\text{on}}\right|}-\sqrt{\left|I_{\text{off}}\right|}\right)/{\left|V_{\text{G}}\right|}^{\max }\right]}^2/\left(\left({WC}_{\text{i}}/2L\right){\mu }_{\text{sat}}\right)$ . The dielectric spectra were measured by a Keysight E4980A LCR meter on the MIS capacitors with series resistance corrected. The luminance of the OLEDs was measured by a TOPCON BM-7AS luminance colorimeter. To characterize the material properties of the PVA layer, we used XPS (Thermo Scientific, Escalab 250Xi), XRF (Rigaku, ZSX Primus II), and Fourier-transform infrared spectroscopy (FTIR) (PerkinElmer, Frontier), and the layer thickness was measured by a stylus profiler (KLA Tencor, D-600).

Impedance measurements were performed using high precision LCR-meter E4980A (Keysight Technologies) in the frequency (f) range 10 kHz—1 MHz. The measured impedance values were interpreted with an equivalent scheme consisting of serially connected capacitor (C_s) and resistor (R_s). The dissipation factor (D) was estimated as 2π × f × R_s. In the case of blanket ZIF films, their k-value was calculated from capacitance C_s measured on MIM stacks using the formula for parallel plate capacitor: k = C_s × d/(ε₀ × S), where ε₀ denotes vacuum permittivity, S denotes area of top 70 nm thick Pt circular electrodes e-beam evaporated through a Ni shadow mask (Pfeiffer PLS580), and d denotes average thickness of ZIF layer extracted from cross-sectional SEM images.

Polydimethylsiloxane (PDMS) elastomer kit was bought from Dow Corning (Midland, MI, USA). Medical polyurethane (PU) films were purchased from Jiaxing Meson Medical Materials Co. Ltd. (Zhejiang, China). Silver NWs in ethanol solution (10 mg mL⁻¹) were brought from Shanghai Bohan Chemical Technology Co. Ltd. (Shanghai, China). Scanning electron microscopy (SEM) imaging was carried out with a JSM-7900F field emission scanning electron microscope operating at an acceleration voltage of 10 kV (JEOL, Tokyo, Japan). The capacitances of the flexible sensor were measured with a precision LCR meter E4980A (Keysight, CA, USA). Pressure performance of the sensors was recorded by a digital tensile testing machine bought from Yueqing Handpi instrument co. LTD (Hunan, China).

The crystalline phase and structure were measured using the X-ray diffraction (XRD) technique (Rigaku Mini Flex II) with Cu K_α radiation (λ = 1.5401 Å). The morphology of the grown nanostructure was identified using a field emission scanning electron microscope (FE-SEM). High resolution-transmission electron microscope (HR-TEM) micrographs of the ZnO nanodisc were obtained using a high resolution JEOL JEM-2100F microscope. Elemental study was performed through energy dispersive spectroscopy using FE-SEM. Fourier-transform infrared spectroscopy (FT-IR) spectra of the ZnO nanodiscs were recorded in the range 400–4000 cm⁻¹ at a 4 cm⁻¹ resolution using a Thermo Scientific Nicolet iS50 FT-IR spectrometer. The dielectric constant and tangent loss of the nanodiscs were measured using a Keysight LCR meter (E4980A) in the frequency range 20 Hz to 2 MHz. The piezoelectric output performance of the ZnO nanodisc based nanogenerator device was determined through a Keithley (6517B) system electrometer (impedance > 200 TΩ).