Friction plays a critical role in dexterous robotic manipulation. However, realizing friction sensing remains a challenge due to the difficulty in designing sensing structures to decouple multi-axial forces. Inspired by the topological mechanics of knots, we construct optical fiber knot (OFN) sensors for slip detection and friction measurement. By introducing localized self-contacts along the fiber, the knot structure enables anisotropic responses to normal and frictional forces. By employing OFNs and a change point detection algorithm, we demonstrate adaptive robotic grasping of slipping cups. We further develop a robotic finger that can measure tri-axial forces via a centrosymmetric architecture composed of five OFNs. Such a tactile finger allows a robotic hand to manipulate human tools dexterously. This work could provide a straightforward and cost-effective strategy for promoting adaptive grasping, dexterous manipulation, and human-robot interaction with tactile sensing.

The ability to sense heat and touch is essential for healthcare, robotics, and human–machine interfaces. By taking advantage of the engineerable waveguiding properties, we design and fabricate a flexible optical microfiber sensor for simultaneous temperature and pressure measurement based on theoretical calculation. The sensor exhibits a high temperature sensitivity of 1.2 nm/°C by measuring the shift of a high-order mode cutoff wavelength in the short-wavelength range. In the case of pressure sensing, the sensor shows a sensitivity of 4.5% per kilopascal with a fast temporal frequency response of 1000 Hz owing to the strong evanescent wave guided outside the microfiber. The cross talk is negligible because the temperature and pressure signals are measured at different wavelengths based on different mechanisms. The properties of fast temporal response, high temperature, and pressure sensitivity enable the sensor for real-time skin temperature and wrist pulse measurements, which is critical to the accurate analysis of pulse waveforms. We believe the sensor will have great potential in wearable optical devices ranging from healthcare to humanoid robots.

为使观瞄系统以简单、紧凑结构实现探测、识别目标功能，选用光学补偿法设计紧凑型双视场可见光镜头。首先，根据视场、作用距离指标完成相机选型和焦距计算，依据已选相机像元尺寸和最低照度计算F数，并分析双视场光学系统的特点；其次，对比常规的光阑位置固定方案与光阑位置切换方案，得出后者在实现光学总长、最大通光孔径、变焦行程有效压缩的同时，可以实现更大的相对孔径和更好的像质；最终，选用光阑位置切换方案设计了由11片透镜构成，光学总长为150 mm，最大通光孔径为Φ42 mm，变焦行程为35.97 mm的紧凑型双视场可见光镜头。该镜头短焦焦距为32 mm，F数为2.3，满足水平视场角不小于12°、探测距离不小于5 km的要求；长焦焦距为126 mm，F数为3，满足水平视场角不小于3°、畸变小于0.5%、识别距离不小于5 km的要求。设计结果表明，对于焦距32 mm和焦距126 mm，全视场调制传递函数（MTF ）均大于0.45，全视场点列图的均方根 （RMS）直径小于或接近4 μm，整体像质良好。公差分析结果表明，在135 cycles/mm处，全视场MTF大于0.3的概率达到90%以上。

现代战争要求战场目标搜索设备能够在机动条件下实现快速自动搜索、发现、识别远距离目标，并对敌方目标进行威胁排序，将目标的坐标进行精确定位后把目标信息传递给后方。提出了一种新型综合的特种车辆观瞄系统，对其5个组成部分−全景组件、可见光连续变焦组件、高性能红外热像仪组件、智能控制组件、云台光机组件进行研究与设计，并对系统的组成、原理以及关键技术作了论述。样机研制后的功能试验和精度测试结果表明，综合观瞄系统原理正确，可靠性高，稳定精度可达0.06 mil（1σ），快速反应能力强，为特种车辆实现城市反恐提供了一种性价比高的观瞄系统。

Chiral metasurfaces based on asymmetric meta-atoms have achieved artificial circular dichroism (CD), spin-dependent wavefront control, near-field imaging, and other spin-related electromagnetic control. In this paper, we propose and experimentally verify a scheme for achieving high-efficiency chiral response similar to CD of terahertz (THz) wave via phase manipulation. By introducing the geometric phase and dynamic phase in an all-silicon metasurface, the spin-decoupled terahertz transmission is obtained. The giant circular dichroism-like effect in the transmission spectrum is observed by using a random phase distribution for one of the circular polarization components. More importantly, the effect can be adjusted when we change the area of the metasurface illuminated by an incident terahertz beam. In addition, we also demonstrate the spin-dependent arbitrary wavefront control of the transmitted terahertz wave, in which one of the circularly polarized components is scattered, while the other forms a focused vortex beam. Simulated and experimental results show that this method provides a new idea for spin selective control of THz waves.

Traditional magnetically coupled resonant wireless power transfer technology uses fixed distances between coils for research, to prevent fluctuations in the receiving voltage, and lead to reduce transmission efficiency. This paper proposes a closed-loop control wireless communication wireless power transfer system with a wearable four-coil structure to stabilize the receiving voltage fluctuation caused by changes in the displacement between the coils. Test results show that the system can provide stable receiving voltage, no matter how the distance between the transmitting coil and the receiving coil is changed. When the transmission distance is 20 mm, the power transfer efficiency of the system can reach 18.5% under the open-loop state, and the stimulus parameters such as the stimulation period and pulse width can be adjusted in real time through the personal computer terminal.