A new strategy for the fabrication of a flexible and highly sensitive capacitive pressure sensor

The development of flexible capacitive pressure sensors has wide application prospects in the fields of electronic skin and intelligent wearable electronic devices, but it is still a great challenge to fabricate capacitive sensors with high sensitivity. Few reports have considered the use of interdigital electrode structures to improve the sensitivity of capacitive pressure sensors. In this work, a new strategy for the fabrication of a high-performance capacitive flexible pressure sensor based on MXene/polyvinylpyrrolidone (PVP) by an interdigital electrode is reported. By increasing the number of interdigital electrodes and selecting the appropriate dielectric layer, the sensitivity of the capacitive sensor can be improved. The capacitive sensor based on MXene/PVP here has a high sensitivity (~1.25 kPa−1), low detection limit (~0.6 Pa), wide sensing range (up to 294 kPa), fast response and recovery times (~30/15 ms) and mechanical stability of 10000 cycles. The presented sensor here can be used for various pressure detection applications, such as finger pressing, wrist pulse measuring, breathing, swallowing and speech recognition. This work provides a new method of using interdigital electrodes to fabricate a highly sensitive capacitive sensor with very promising application prospects in flexible sensors and wearable electronics.

A Plasmon Modulator by Directly Controlling the Couple of Photon and Electron

As a strong couple mode of photon and electron collective oscillation, the movement of an electron can affect the collective plasmon behaviors efficiently. In this paper, we proposed a novel method for modulating the plasmon by directly controlling the movement of the electron but independent of the properties of the medium. This method is demonstrated by a hybrid graphene-dielectric-interdigital electrode structure in the mid-infrared range. It is possible to regulate the confinement of the graphene carrier and stimulate the plasmon in real-time by using the potential wells created by interdigital electrodes. Furthermore, the plasmon frequency can also be modulated utilizing changing the confined area and the density of the carrier. As a result. the frequency has been tuned over a range of ~ 33 cm−1 by applying voltage, and the maximum extinction ratio we measured is 8%. Due to the movement of the electron can also be driven optically, these findings may define a new approach to the all-optical modulator with low pump power.

Optimization Design Strategy of Electroadhesive Devices with Interdigital Electrodes Based on the Multiparameters Theoretical Model

Electroadhesion is an adhesion mechanism applying high voltage to generate adhesive force. The electroadhesion system can generate and maintain adhesive force on almost any object, solving the challenge of handling irregular and rough surface objects as well as fragile objects. The electroadhesive pad is a key component of the electroadhesion system for interacting with the target object. By optimizing the design of the electroadhesive pad, the electroadhesion system provides greater adhesive force and achieves better adhesion. In this study, a multiparameter theoretical model including the dimensional parameters of the electroadhesive pad has been developed and an optimization design strategy for specific applications has been proposed. By considering both the key parameters influencing the electroadhesive force and the practical constraints of equipment and materials, this strategy allows the optimization design methods of electroadhesive pads to be further extended to applications. The influence of each parameter on the optimization results has been evaluated by calculating and comparing the optimized values under different conditions, and it has been demonstrated that the size of the pad also has an effect on the optimized values. A 3D simulation model has been established to simulate the effect of electroadhesion, and the accuracy of the optimization results has been verified by comparing the theoretical and simulation results. An application example has been performed and the results have shown that the structure of the electroadhesive pad can be optimized by using this strategy, thus maximizing the generated electroadhesive force and improving the overall performance of the electroadhesion system.

Pyroelectric Properties of BaxSr(1−x)TiO3/PVDF-TrFE Coating on Silicon

Bilayer coatings of barium strontium titanate (BaxSr(1−x)TiO3)/poly [(vinylidenefluoride-co-trifluoroethylene] (PVDF-TrFE) were integrated on silicon Si (100) for pyroelectric devices. Pyroelectric properties of the composite were determined for different electrode materials (silver and aluminum) and different electrodes configurations creating an electric field in parallel and in-plane direction in the ferroelectric coating. For this purpose, parallel-plate and planar interdigital capacitors were fabricated. Anisotropy in the pyroelectric response was noted for the different directions of the measured electrical potential. The dynamic method was used to evaluate the pyroelectric properties in the temperature range of 22 to 48 °C. Pyroelectric response with a higher value was observed at the one plate’s configuration of interdigital electrodes. The voltage response was the strongest when silver contacts were used. At temperatures near room temperature, the voltage increased by 182 µV at resolution of 7 µV/°C for the in-plain device configuration, vs. 290 µV at a resolution of 11 µV/°C for the out-of-plain configuration. A relationship between the surface morphology of the ferroelectric oxide and oxide/polymer coating and the pyroelectric voltage was also found, proving the smoothening effect of the introduction of polymer PVDF-TrFE over the BaSrTiO3 grains.