Porous elastomer has been used as the dielectric layer of capacitive pressure sensors to reduce the Young’s modulus and improve the sensitivity. In this article, influence of permittivity on the sensitivity of porous elastomer-based capacitive pressure sensors is investigated. By introducing metallic particles (silver nanoparticles) into porous elastomer (polydimethylsiloxane) to increase its permittivity, the sensitivity of the porous composite-based capacitive pressure sensor is improved by 101.5% in the low-to-medium pressure regime (0-100 kPa). The capacitive pressure sensor also shows high linearity, good durability, and high noise-immunity. Due to its high sensitivity, an artificial hand based on the capacitive pressure sensor can detect tiny pressure changes induced by wrist pulse and derive pressure distribution on different phalanges.

Resistive pressure sensors generally employ microstructures such as pores and pyramids in the active layer or on the electrodes to reduce the Young’s modulus and improve the sensitivity. However, such pressure sensors always exhibit complex fabrication process and have difficulties in controlling the uniformity of microstructures. In this paper, we demonstrated a highly sensitive resistive pressure sensor based on a composite comprising of low-polarity liquid crystal (LPLC), multi-walled carbon nanotube (MWCNT), and polydimethylsiloxane (PDMS) elastomer. The LPLC in the PDMS forms a polymer-dispersed liquid crystal (PDLC) structure which can not only reduce the Young’s modulus but also contribute to the construction of conductive paths in the active layer. By optimizing the concentration of LC in PDMS elastomer, the resistive pressure sensor shows a high sensitivity of 5.35 kPa⁻¹, fast response (<150 ms), and great durability. Fabrication process is also facile and the uniformity of the microstructures can be readily controlled. The pressure sensor offers great potential for applications in emerging wearable devices and electronic skins.

We present a 1D/2D switchable grating based on field-induced polymer stabilized blue phase liquid crystal (PSBPLC). For 1D grating, the diffraction efficiency of the first order is 37.2% and the phase modulation depth of the 1D grating can achieve 2π. For 2D grating, more than 90% of light intensity is distributed to the surrounding orders of zero order and the phase modulation depth is about 3.67π. Furthermore it shows fast phase modulation and 1D/2D switching time.

Thermal-resistance temperature sensors generally employ temperature-sensitive materials as active layers, which are always deposited on a flexible substrate to improve flexibility. Such a temperature sensor is usually integrated in wearable devices with other sensors, such as pressure sensors and stretchable sensors. In prior works, the temperature and pressure sensors are usually located in different layers in a multifunction sensor, which results in a complicated fabrication process, as well as a large thickness of devices. Meanwhile, many temperature sensors are based on large areas of non-transparent materials, leading to difficulties in integrating display applications. In this paper, we demonstrate a flexible temperature sensor based on polyaniline/graphene (GPANI)–polyvinyl butyral (PVB) thin film and indium tin oxides (ITO)- polyethylene terephthalate (PET) substrates. The GPANI particles embedded in PVB film not only contribute to temperature detection, but also response to external pressures, due to weak deformations. In addition, the thin composite film (2.7 μm) highly improved the transparency. By optimizing the device structure, the sensor integrates temperature and pressure detection into one single layer, which shows a wide temperature range of 25–80 °C, a pressure range of 0–30 kPa, and a high transparency (>80%). The temperature sensor offers great potential for applications in emerging wearable devices and electronic skins.

Multi-view three-dimensional (3-D) displays using directional beam splitter array were proposed to achieve a perfect 3-D perception with low cross-talk. The multi-direction collimated light may project different images to different viewing zones to form the multi-view autostereoscopic display. Furthermore, a high resolution 3-D display can be realized with a sequential beam splitter array and a sequential liquid crystal display. By optimization, the cross-talk of the directional beam splitter backlight system was lowered to 5% to improve the perception of the 3-D displays.

A small amount of polyaniline functionalized graphene (G–PANI, 0.03–2.00%) nanosheets was doped into conventional polymer-stabilized blue phase liquid crystals (PS-BPLCs), and the electro-optical property effects were studied. The driving capability of BPLCs can be much improved in that the Kerr constant of BPLCs doped with 0.05 wt% G–PANI is increased by ∼55% compared with that of BPLCs without G–PANI. Meanwhile, this composite exhibits no degradation of electro-optical properties, such as response time, hysteresis and residual birefringence.