Electronic sensors play important roles in various applications, such as industry and environmental monitoring, biomedical sample ingredient analysis, wireless networks and so on. However, the sensitivity and robustness of current schemes are often limited by the low quality‐factors of resonators and fabrication disorders. Hence, exploring new mechanisms of the electronic sensor with a high‐level sensitivity and a strong robustness is of great significance. Here, a new way to design electronic sensors with superior performances based on exotic properties of non‐Hermitian topological physics is proposed. Owing to the extreme boundary‐sensitivity of non‐Hermitian topological zero modes, the frequency shift induced by boundary perturbations can show an exponential growth trend with respect to the size of non‐Hermitian topolectrical circuit sensors. Moreover, such an exponential growth sensitivity is also robust against disorders of circuit elements. Using designed non‐Hermitian topolectrical circuit sensors, the ultrasensitive identification of the distance, rotation angle, and liquid level is further experimentally verified with the designed capacitive devices. The proposed non‐Hermitian topolectrical circuit sensors can possess a wide range of applications in ultrasensitive environmental monitoring and show an exciting prospect for next‐generation sensing technologies.

Wireless sensor network (WSN) is an interestingly promising technology with many applications in intelligent environment-monitoring. Its energy consumption is, however, essentially challenged after it is deployed. In this paper, we developed a low-resonant-frequency piezoelectric energy harvesting device as an alternative to power WSN deployed in a weak vibration environment. An energy management module, equipped with a full-bridge rectifier (FBR), a fully self-powered voltage controller, and a logic-level protection circuit was designed to enable a regulated voltage to intermittently drive WSN for temperature monitoring. The power transfer efficiency of FBR reached 42%, presenting a good performance/cost ratio in the case of a relatively high open-circuit voltage of 8 V and a low rectified voltage of 3.3 V. The experimental results have demonstrated that the proposed WSN was successfully driven at an interval time of less than 1 min, and fully self-powered by the scavenged energy from the environmental vibration source of a 0.15-g acceleration and a 40-Hz vibration frequency.

Electret-based rotational energy harvesting (EBREH) technology is promising to overcome the electrostatically converted power limitation of velocity-damped resonance generators. Its structural parameter-dominated capacitance variation and parasitic capacitance should be correctly evaluated for the optimal design of EBREH devices regarding the high power output implement. Basically, finite-element analysis (FEA) seems the only access to predict capacitances across the complicated interdigitated electrodes in 3-D space because of partially or completely neglected fringing effects in currently available theoretical models. In this paper, we proposed a more efficient model for the capacitance of EBREH devices based on four-positioned capacitors, i.e., coplanar, parallel-plate, flat-plate nonparallel, and sector coplanar capacitors. Distinctively differing from other models, our model takes 3-D fringing effects associated with fringing fields into account properly in each type of the capacitor. In addition, the accuracy of the proposed model was much improved by combining parallel-wire capacitance theory and Schwarz-Christoffel mapping. Our model was verified through both the FEA and practical measurements with a fabricated EBREH structure. The measurement indicated that this novel capacitance model can be readily applicable to rotary and linear motion-driven EBREH devices and electrostatic sensors for further design optimizations with device parameters.

Sensors are of fundamental importance and widely used in modern society, such as in industry and environmental monitoring, biomedical sample ingredient analysis and wireless networks. Although numerous sensors have been developed, there is a continuous demand for sensors with increased sensitivity, to detect signals that were previously undetectable. Recently, non-Hermitian degeneracies, also known as exceptional points (EPs), have attracted attention as a way of improving the responsiveness of sensors. In contrast to previous investigations, here we present a new approach to achieving ultra-sensitivity by reconstructing exceptional systems. In the reconstruction process, some eigenstates near the previous EPs are utilized, and non-reciprocal long-range couplings are introduced. The sensitivities of our reconstructed systems have improved by several orders of magnitude compared to those based on EPs. Furthermore, we design and fabricate corresponding integrated circuit sensors to demonstrate the scheme. Our work paves the way for the development of highly sensitive sensors, which have a wide range of applications in various fields.

With the development of micro technology, the fuse for small-caliber projectiles tends to be miniaturized and intelligent, the traditional fuse no longer meets the requirements. In this paper, we demonstrate a micro safety and arming (S & A) device with small volume and high reliability in small caliber projectile platforms. The working principle of S & A devices is that a centrifugal insurance mechanism could deform under a centrifugal load and thus cause fuse safety arming. The centrifugal insurance mechanism is designed theoretically, verified by simulation and experimental methods. The experimental results show that, when the rotary speed is over 36,000 rpm, the fuse was armed safely. In addition, the experimental, simulation, and theoretical results are basically consistent, and indicate that the centrifugal insurance mechanism meets the expected criteria.

In conventional gap-closing electret-biased electrostatic energy harvesting (EEEH) schemes, electrets with a very low ratio of electret thickness to permittivity are in great demand to allow the attainment of high power output. However, in practice, pursuing such a low ratio introduces unwanted burdens on the electret stability and therefore the reliability of the EEEH devices. In this paper, we propose a dielectric-oscillator-based electrostatic EH (DEEH) scheme as an alternative approach to harvesting electret-biased electrostatic energy. This approach permits the fabrication of an electret-free closed EH circuit. The DEEH architecture directly collects the electrical energy exclusively through the oscillating dielectric body and thus completely circumvents the restrictions imposed by the electret parameters (thickness and permittivity) on power generation. Significantly, without considering the electret thickness and permittivity, both theoretical analysis and experiments have verified the effectiveness of this DEEH strategy, and a high figure of merit (on the order of 10⁻⁸ mW cm⁻²V⁻²Hz⁻¹) was achieved for low-frequency movements.