MEMS safety and arming device (SAD) with merits of small size and easy integration is one of the most promising candidates for the fuze to realize miniaturization, integration and intelligence. In ...this paper, a novel inertia-driven MEMS SAD with three independent safety features is proposed. The SAD placed perpendicular to the projectile axis is beneficial to reduce the size and improve the detonation energy transfer efficiency. The dynamic finite element simulations are carried out to study the mechanical responses of the device under dual-environment inertial loads. The response behaviors of the setback and centrifugal safety features and interrupter under different loads are elucidated and discussed. A series of experiments are performed to verify the simulation analysis results and investigate the safety and arming performances. The results indicate that the proposed MEMS SAD with small size and compact structure has successfully achieved safety and arming performances. The experimental results are in good agreement with the simulated analysis results.
The cure rate for metastatic osteosarcoma has not substantially improved over the past decades. Clinical trials of anti-HER2 trastuzumab or anti-GD2 dinutuximab for metastatic or refractory ...osteosarcoma were not successful, and neither was immune checkpoint inhibitors (ICIs).
We tested various target antigen expressions on osteosarcoma cell lines using flow cytometry and analyzed in vitro T cell engaging BsAb (T-BsAb)-dependent T cell-mediated cytotoxicity using 4-h
Cr release assay. We tested in vivo anti-tumor activities of T-BsAb targeting GD2 or HER2 in established osteosarcoma cell line or patient-derived xenograft (PDX) mouse models carried out in BALB-Rag2
IL-2R-γc-KO (BRG) mice. We also generated ex vivo BsAb-armed T cells (EATs) and studied their tumor-suppressive effect against osteosarcoma xenografts. In order to improve the anti-tumor response, ICIs, anti-human PD-1 (pembrolizumab) or anti-human PD-L1 (atezolizumab) antibodies were tested their synergy with GD2- or HER2-BsAb against osteosarcoma.
GD2 and HER2 were chosen from a panel of surface markers on osteosarcoma cell lines and PDXs. Anti-GD2 BsAb or anti-HER2 BsAb exerted potent anti-tumor effect against osteosarcoma tumors in vitro and in vivo. T cells armed with anti-GD2-BsAb (GD2-EATs) or anti-HER2-BsAb (HER2-EATs) showed significant anti-tumor activities as well. Anti-PD-L1 combination treatment enhanced BsAb-armed T cell function in vivo and improved tumor control and survival of the mice, when given sequentially and continuously.
Anti-GD2 and anti-HER2 BsAbs were effective in controlling osteosarcoma. These data support the clinical investigation of GD2 and HER2 targeted T-BsAb treatment in combination with immune checkpoint inhibitors, particularly anti-PD-L1, in patients with osteosarcoma to improve their treatment outcome.
The design and characterization of a MEMS based rotary SAD (Safety and Arming Device) are proposed. In order to improve the level of system’s safety, the SAD is encrypted by the different tooth ...thickness on the rotary interrupter. To simplify the configuration of the SAD, discriminator has been integrated into the trap teeth of interrupter. And the MEMS safety and arming device with the feature of self-assembly, is fabricated on SOI wafer with only 3 pieces of lithographic mask.
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•The encryption mechanism of the on-chip SAD has been realized through different tooth thickness on the rotary interrupter.•The amplitude and the timing sequence recognition of input voltages have been achieved through the meshing between the pawls and the teeth on the interrupter with different tooth thickness.•The pawl will be captured by the trap and be locked up by the blade, if error decoding voltage has been detected.•The design of rotational actuation makes the conversion between safety status and arming status resettable.•The displacement output of the pawl could be accumulated clockwisely, and the interrupter is able to rotate around the central axis as a wheel.
The Safety and Arming Device (SAD) is the essential component that prevents fuze arming until specific conditions have been achieved. The core principle of safety and arming mechanism is the interruption of energy transfer, usually explosion, laser, or high-speed slapper, with a movable interrupter. In the present research, the design and characterization of a MEMS based on-chip SAD are proposed. Comparing with the previous research, the novelty of present work mainly lies in the rotary encryption mechanism of interrupter, which makes the SAD safer and resettable. Furthermore, the SAD is encrypted by the different tooth thickness on the rotary interrupter, which associates with specified decoding voltage. Once the input voltage fails to meet the encryption criteria, the pawl of electrothermal actuator will be captured by the trap in the tooth of interrupter, then the whole system will be locked up. And fabricated on SOI (silicon-on-insulator) wafer with a dimension of 13.4 mm × 9.3 mm × 0.454 mm, it’s easy for the on-chip SAD to be integrated in the microfuze or be applied in the information security system for hard-disk encryption. In addition, with the position holding mechanism provided by the double clamped V-shape beam, each single step’s movement of interrupter can be accumulated in the rotary direction, which may provide a way to tackle the contradiction between displacement output and force output of MEMS actuator.
This article presents an efficient methodology for assessing the structural failure of micro-electromechanical systems (MEMS) used in safety and arming device (SAD) while taking into account the ...effect of fabrication errors. The proposed methodology uses statistical characteristics that are assessed using nonintrusive polynomial chaos expansion (PCE) to consider uncertainty. The effectiveness of the methodology is demonstrated by considering the example of the latching feature in MEMS SAD and comparing the results with experimental data obtained from a fabricated prototype. The proposed methodology accurately determines the failure probability and sensitive parameters of the sample, and provides insights into the impact of fabrication errors on the structural failure of the sample. It achieves the objective of reducing the burden of repetitive finite-element analysis (FEA) in uncertainty analysis and provides an efficient way to account for uncertainty in the study of MEMS devices.
Although many believe that unmanned aerial vehicles or drones are a recent invention, unmanned flight has a rich history that goes all the way back to ancient times. The first systems that can be ...specified under the modern definition of unmanned aerial vehicles or drones include reconnaissance drones developed and deployed during the Cold War period. Today, such systems have evolved and can have different designs. In the last twenty years, many drones with different aerodynamic characteristics, flight endurance, methods and places of launch and acceptance, and even more diverse purposes have been developed. The achievements of modern science, technique, and technology, especially in the field of microelectronics and control systems, have made it possible to design and manufacture drones that are capable of performing controllable flight in a wide range of altitudes, speeds, and distances while performing complex and diverse tasks with almost the same efficiency as well as manned aircraft. This book provides a comprehensive overview of drone technology and applications with chapters on the detection and classification of drones, issues related to electric unmanned aerial vehicles, integrating drones into educational curricula, and the uses of different types of drones in various situations, among other topics.
While previous studies have assessed public opinions for arming teachers in K-12 schools in the United States, comparatively less research has focused on understanding teachers' opinions for such ...policies and assessed whether and to what extent school- and individual-level factors are associated with differences in support. The current study aims to address these voids in the current body of literature by analyzing self-report data from a large sample of Texas K-12 educators (N = 9,196) to assess relations between theoretical correlates of teacher and staff gun carrying, demographic as well as school characteristics, and support for carrying. A series of logistic regression models reveal that favorable views of an emergency operation plan in a school setting and general negative view of guns in school are associated with lower odds of support. The strength of these associations varies across teacher and school characteristics. The implications of the reported results for K-12 school policy is discussed.
Tumor-selective replicating “oncolytic” viruses are novel and promising tools for immunotherapy of cancer. However, despite their first success in clinical trials, previous experience suggests that ...currently used oncolytic virus monotherapies will not be effective enough to achieve complete tumor responses and long-term cure in a broad spectrum of cancers. Nevertheless, there are reasonable arguments that suggest advanced oncolytic viruses will play an essential role as enablers of multi-stage immunotherapies including established systemic immunotherapies. Oncolytic adenoviruses (oAds) display several features to meet this therapeutic need. oAds potently lyse infected tumor cells and induce a strong immunogenic cell death associated with tumor inflammation and induction of antitumor immune responses. Furthermore, established and versatile platforms of oAds exist, which are well suited for the incorporation of heterologous genes to optimally exploit and amplify the immunostimulatory effect of viral oncolysis. A considerable spectrum of functional genes has already been integrated in oAds to optimize particular aspects of immune stimulation including antigen presentation, T cell priming, engagement of additional effector functions, and interference with immunosuppression. These advanced concepts have the potential to play a promising future role as enablers of multi-stage immunotherapies involving adoptive cell transfer and systemic immunotherapies.
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•The competitive merits of piezoelectric motor for the S&A (safety and arming device) are analyzed in detail.•An H-shaped piezoelectric motor based S&A is proposed, designed and ...fabricated based on the concept of self-moving.•The design procedures and working mechanisms are explained and experimentally verified.•The designed piezoelectric motor based S&A can change its state from safety to arming or reversely within 25 ms.
In this contribution, an H-shaped piezoelectric motor based safety and arming device that is driven by the hybrid of symmetrical first longitudinal mode and second bending mode is proposed, designed and experimental investigated. The proposed system operates based on the concept of self-moving and show potential infield of fuse system with different calibers. The actuating mechanism is that the four driving feet contact with the guides alternately and push the motor to move continuously. Modal and harmonic analysis are conducted to determine the dimension of the structure, confirm the working principle and analyze the motion trajectories of driving feet with finite element method. It is shown that trajectories of the driving feet are oblique ellipses with different angles because of the asymmetry of structure. In addition, a prototype is fabricated and experimented. The results show that the average speeds of the prototype in two directions are 120.6 mm/s and 130.1 mm/s respectively under the driving voltage of 120 V0-p and working frequency of 88.5 kHz. The H-shaped piezoelectric motor based safety and arming device can change its state from safety to arming or reversely in 25 ms with the fixed stroke of 3 mm.
To improve the reliability and safety of the micro-electro-mechanical system (MEMS) safety and arming devices (SAD), this paper investigated the dynamic response of the cantilever-type MEMS setback ...arming device under impact loads. Based on the modal superposition method, the dynamic response of the structure is analyzed using the Euler-Bernoulli beam theory. The continuous dynamics model considering the self-weight of the cantilever was established. And the established model can obtain the dynamic response of the entire structure under impact loads. Moreover, the influence of structure parameters on the dynamic characteristics was analyzed by theoretical analysis. The results obtained in the theoretical analysis are highly in agreement with the finite element method (FEM) simulation. Furthermore, the maximum displacement and its occurrence time at fundamental frequency are given. The dynamic visualization experiment was employed for the cantilever-type MEMS setback arming device under impact loads. Multiple experiments showed that the established theoretical model is in high agreement with the experimental results. The dynamic response of the cantilever-type MEMS setback arming device under impact loads is significant for improving the reliability and safety of the system. It provides theoretical guidance for the optimization design.
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