The thermal characteristics of bearing rotating elements are essential for the service evaluation of bearing. However, the existing monitoring methods are limited by bearing internal complex structure and extreme operating environment. Hence, based on the monitoring technology of CdTe quantum dots (QDs) sensor, an improved QDs sensor was fabricated by process optimization and polymers coating, which enables bearing rotating elements thermal monitoring for extreme working condition. First, the principle of the measurement was introduced and the existing problems were analyzed. Then, the influence of preparation process on temperature-dependent photoluminescence (PL) spectra of CdTe QDs was investigated. The performance improvement methods of the QDs sensor, both organic coating and inorganic coating, were investigated. The fabricated sensor named CdTe@PVA presents remarkable improved performance in fluorescence intensity, highest tolerable temperature and stability. In the end, a rolling bearing experimental rig was set up and the temperature of the bearing cage at different rotation speeds were captured by using the proposed CdTe@PVA sensor.

This work presents a novel variable stiffness structure consisting of a fiber-constrained dielectric elastomer tube filled with insulating oil. The tensile stiffness of the structure can be adjusted by voltages and its initial value can be customized according to the initial pre-stretch of the material. The structure has a dimension of ∼30 mm diameter × 50 mm length. A mathematical analysis is established to predict the initial tensile stiffness of the structure. The changes of the tensile stiffness of the structure under voltages are verified experimentally. The results show a decrease of the tensile stiffness of the device by 25% at 4 kV and the decrement is also related to the elongation of the structure. With different pre-stretches and dimensions of the dielectric elastomer, one can obtain devices with different variation ranges of tensile stiffness.

This paper presents an inchworm inspired soft robot composed of the soft body, the front foot as well as the back foot. Compared to the traditional inchworm-type robot consisting of rigid components, the driven mode for the soft robot is more simple. The soft robot inspired by the inchworm has higher locomotion efficiency than the other bionic soft robot. The main idea of this paper is to imitate the “Ω” motion shape of biology inchworm based on a silicone square tube with strain-limiting layers. Besides, each foot of the robot made through 3D printing technology together with metal sheet can produce different friction coefficients to achieve the anchor-motion movement. Then, the robot realizes an inchworm-like locomotion under certain actuation patterns. Experimental results show that the proposed robot has excellent performance.