# Underwater Highly Pressure-Sensitive Fabric Based on Electric-Induced Alignment of Graphene
## 3 Results and Discussion
The different dielectric properties and conductivity between graphene nanosheets and macromolecular PDMS lead to the induced dipole moment (\(\mu\)). Here the dipole moment can be divided into two directions--the component parallel to the graphene sheet \(\mu_{\perp}\) and the component perpendicular to the graphene sheet \(\mu_{\perp}\)--and the force acting on the graphene sheet is the superposition of the two effects [27]. The interaction between the electric field force and dipole moment produces an electric field-induced torque \(T=\mu\times E\), which is the driving force for the electric field to align the graphene, and the torque will try to twist the graphene, so that the graphene is aligned parallel to the electric field. However, due to the large aspect ratio of graphene, the generated dipole moment usually differs from the direction of the applied electric field force. The overall force acting on a graphene sheet is the superposition of moments caused by fields parallel and perpendicular to its axis; note that \(E_{\parallel\,1}=E\times\cos\theta\); \(E_{\perp}\)= \(E\times\sin\theta\), and \(\theta\) is the angle between the direction of the DC electric field and sheet axis. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{1}{c}{**Articles**} & \multicolumn{1}{c}{**Approaches**} & \multicolumn{1}{c}{**Materials**} & \multicolumn{1}{c}{**Response/Recovery**} \\  & & & **Times** \\ \hline ours & Dipping/electric field & Graphene/PDMS & 100 ms/100 ms \\ [PERSON] et al. [24] & Spraying & MWCNTs/SEBS & / \\ [PERSON] et al. [25] & brush & CNF/PVDF/PDMS & / \\ [PERSON] et al. [26] & Dipping & Ti\({}_{3}\)C\({}_{2}\)Tx MXene & 300 ms/260 ms \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison between our work and related reported research. Figure 1: Preparation of superhydrophobic conductive fabrics. (**a**) Schematic diagram of the preparation of superhydrophobic conductive fabrics by electric field, Ar plasma treatment. (**b**) Scanning electron microscope images show the surface morphology of the fibers before and after treatment, with the inset showing the state of the dyed water droplets on the fabric surface. (**i**) is untreated fabric, (**ii**) is the fabric after PDMS/graphene wrapping. Scale bar: 25 \(\upmu\)m. (**c**) Schematic diagram of the reaction principle between PDMS and polyester fibers in the plasma reaction chamber. When \(\theta\) satisfies certain conditions, the total force can deflect the graphene sheet against the resistance in the system. If the directional arrangement of graphene is achieved under an electric field, the main consideration is the relationship between the torque and resistance of the system, and graphene starts to deflect when the torque generated under the electric field exceeds the sum of the resistance of the graphene in the system. Therefore, the choice of electric field strength is an important starting point for achieving the directional deflection of graphene. The physical properties of the sensors are important for their performance. Therefore, the superhydrophobicity, electrical conductivity, and wear resistance of the sensors are discussed. Pressure sensors were assembled with graphene@PDMS samples with different graphene loadings and measured by an electrochemical workstation. As shown in the inset of Figure 3a, the changes in I\(-\)V curves of the single-layer fabrics with different graphene loadings are linear and pass through the origin, following [PERSON]'s law. The relative change in current (\(\Delta\)I/I\({}_{0}\), \(\Delta\)I = I \(-\) I\({}_{0}\), where I is the instantaneous current, I\({}_{0}\) is the initial current at 0 kPa) is defined as the signal response of the pressure sensor, which can indirectly represent the sensitivity of the pressure sensor. The \(\Delta\)I/I\({}_{0}\) values initially increased and reaches an equal value then decreased as the dispersion concentration increased (Figure 3a).