A multi degree of freedom IPMC active catheter with controllable bending ability under a low voltage (∼1.0 V) was developed.

Flexible electronics has received widespread concern and research. As a most-fundamental step and component, polymer metallization to introduce conductive electrode is crucial in successful establishment and application of flexible and stretchable electronic system. Ionic polymer–metal composite (IPMC) is such an attractive flexible mechanical sensor with significant advantages of passive and space-discriminative capability. Generally, the IPMC sensor is fabricated by the electroless plating method to form structure of ionic polymer membrane sandwiched with two metallic electrodes. In order to obtain high-quality interface adhesion and conductivity between polymer and metal, the plating process for IPMC sensor is usually time-consuming and uncontrollable and has low reproducibility, which make it difficult to use in practice and in large-scale. Here, a manufacturable method and equipment with short processing time and high reproducibility for fabricating IPMC sensors by in situ plasma etching and magnetron sputtering depositing on flexible substrates is developed. First, the new method shortens the fabrication period greatly from 2 weeks to 2 h to obtain IPMC sensors with sizes up to 9 cm × 9 cm or arrays in various patterns. Second, the integrated operation ensures all sample batch stability and performance repeatability. In a typical IPMC sensor, nearly 200 mV potential signal due to ion redistribution induced by bending strain under 1.6% can be produced without any external power supply, which is much higher than the traditional electroless plating sensor. This work verified that the in situ plasma etching and magnetron sputtering deposition could significantly increase the interface and surface conductivity of the flexible devices, resulting in the present high sensitivity as well as linear correlation with strain of the IPMC sensor. Therefore, this introduced method is scalable and believed to be used to metalize flexible substrates with different metals, providing a new route to large-scale fabrication of flexible devices for potential wearable applications in real-time monitoring human motion and human–machine interaction.

Herein, an extended gate-AlGaN/GaN high electron mobility transistor (EG-AlGaN/GaN HEMT) with a high sensitivity for bioassay has been developed. The major difference between the EG-AlGaN/GaN HEMT transducer and a traditional AlGaN/GaN HEMT transducer is the sensing region. By extending the gate electrode and separating the sensing region from the channel of the AlGaN/GaN HEMT, our EG-AlGaN/GaN HEMT has a much larger sensing area and therefore achieves a low limit of detection (0.1 pg mL⁻¹). Additionally, our transducer exhibits excellent linearity (R² = 0.9934) with a wide range (from 0.1 pg mL⁻¹ to 100 ng mL⁻¹). We also demonstrate that the larger area of the extended sensing region can provide a larger current response of the transducer. The results give a proof-of-concept demonstration of the utilization of the EG-AlGaN/GaN HEMT for trace-level biological detection.

Piezoelectric micromechanical ultrasonic transducers (pMUTs) are new types of distance sensors with great potential for applications in automotive, unmanned aerial vehicle, robotics, and smart homes. However, previously reported pMUTs are limited by a short sensing distance due to lower output sound pressure. In this work, a pMUT with a special dual-ring structure based on scandium-doped aluminum nitride (ScAlN) is proposed. The combination of a dual-ring structure with pinned boundary conditions and a high piezoelectric performance ScAlN film allows the pMUT to achieve a large dynamic displacement of 2.87 μm/V and a high electromechanical coupling coefficient ($k_t^2$) of 8.92%. The results of ranging experiments show that a single pMUT achieves a distance sensing of 6 m at a resonant frequency of 91 kHz, the farthest distance sensing registered to date. This pMUT provides surprisingly fertile ground for various distance sensing applications.

Visual-Inertial Odometry (VIO) provides a robust localization solution for Simultaneous Localization and Mapping (SLAM) systems. Self-supervised VIO, a leading approach, has the advantage of not requiring extensive ground-truth labels. Regrettably, this method still poses challenges for robotic applications, particularly unmanned aerial vehicles (UAVs), due to its computational complexity arising from inadequate model designs. To address this bottleneck, we introduce BotVIO (where “Bot” refers to “robotics”), a Transformer-based self-supervised VIO model, offering an excellent solution to alleviate computational burdens for robotics. Our lightweight backbone combines shallow CNNs with spatial-temporal-enhanced Transformers to replace conventional architectures, while the minimalist cross-fusion module uses single-layer cross-attention to enhance multimodal interaction. Extensive experiments show that, during pose estimation, BotVIO achieves a remarkable 70.37% reduction in trainable parameters and a 74.85% decrease in inference speed, reaching up to 57.80 fps on an NVIDIA Jetson NX (10W&2CORE), while improving pose accuracy and robustness. For the benefit of the community, we make public the source code.¹¹https://github.com/wenhuiwei-ustc/BotVIO