Static and Dynamic Analysis of Electrostatically Actuated MEMS Shallow Arches for Various Air-Gap Configurations

In this research, we investigate the structural behavior, including the snap-through and pull-in instabilities, of in-plane microelectromechanical COSINE-shaped and electrically actuated clamped-clamped micro-beams resonators. The work examines various electrostatic actuation patterns including uniform and non-uniform parallel-plates airgap arrangements, which offer options to actuate the arches in the opposite and same direction of their curvature. The nonlinear equation of motion of a shallow arch is discretized into a reduced-order model based on the Galerkin’s expansion method, which is then numerically solved. Static responses are examined for various DC electrostatic loads starting from small values to large values near pull-in and snap-through instability ranges, if any. The eigenvalue problem of the micro-beam is solved revealing the variations of the first four natural frequencies as varying the DC load. Various simulations are carried out for several case studies of shallow arches of various geometrical parameters and airgap arrangements, which demonstrate rich and diverse static and dynamic behaviors. Results show few cases with multi-states and hysteresis behaviors where some with only the pull-in instability and others with both snap-through buckling and pull-in instabilities. It is found that the micro-arches behaviors are very sensitive to the electrode’s configuration. The studied configurations reveal different possibilities to control the pull-in and snap-through instabilities, which can be used for improving arches static stroke range as actuators and for realizing wide-range tunable micro-resonators.

Soft, tough, and fast polyacrylate dielectric elastomer for non-magnetic motor

Dielectric elastomer actuators (DEAs) with large electrically-actuated strain can build light-weight and flexible non-magnetic motors. However, dielectric elastomers commonly used in the field of soft actuation suffer from high stiffness, low strength, and high driving field, severely limiting the DEA’s actuating performance. Here we design a new polyacrylate dielectric elastomer with optimized crosslinking network by rationally employing the difunctional macromolecular crosslinking agent. The proposed elastomer simultaneously possesses desirable modulus (~0.073 MPa), high toughness (elongation ~2400%), low mechanical loss (tan δm = 0.21@1 Hz, 20 °C), and satisfactory dielectric properties ($${\varepsilon }_{{{{{{\rm{r}}}}}}}$$ ε r = 5.75, tan δe = 0.0019 @1 kHz), and accordingly, large actuation strain (118% @ 70 MV m−1), high energy density (0.24 MJ m−3 @ 70 MV m−1), and rapid response (bandwidth above 100 Hz). Compared with VHBTM 4910, the non-magnetic motor made of our elastomer presents 15 times higher rotation speed. These findings offer a strategy to fabricate high-performance dielectric elastomers for soft actuators.

Development of ‘ibuki’ an electrically actuated childlike android with mobility and its potential in the future society

In this paper, we present an electrically driven childlike android named ibuki equipped with a wheeled mobility unit that enables it to move in a real environment. Since the unit includes a vertical oscillation mechanism, the android can replicate the movements of the human center of mass and can express human-like upper-body movements even when moving by wheels. Moreover, providing 46 degrees of freedom enables it to perform various human-like physical expressions. The development of ibuki, as well as the implementation and testing of several functions, is described. Finally, we discuss the potential advantages and future research direction of a childlike mobile android.

Hardware-free collision detection and braking for securing drone propellers

Purpose The widespread use of drones among the general public has led to an alarming increase in accidents, some with lethal consequences. As drone blades are made from rigid materials and rotate at very high speeds, their impact with a human body can result in fatal injuries. Reliable collision detection combined with near-instantaneous braking of the drone’s rotor(s) can substantially lessen the severity of injuries sustained. The purpose of this paper is to achieve a safety solution which can be easily integrated into new products, or retrofitted into existing systems. Design/methodology/approach Through a proof of concept, this paper demonstrates the possibility of detecting a collision with a drone propeller absent any hardware modifications to the drone’s instrumentation. The solution relies on current-sensor readings, ordinarily used for monitoring the battery status of electrically actuated drones. The braking is achieved purely by reconfiguring the motor’s control strategy, without the need for additional hardware, as has been the case in previous works. Findings This paper demonstrates the possibility of detecting a collision with a drone propeller absent any hardware modifications to the drone’s instrumentation. Originality/value Compared to previous works which require installing additional hardware, the solution is purely software. This makes it very easy to integrate into existing systems or new products, at no additional cost. In experiments conducted on a prototype system, the solution was shown capable of detecting a collision and braking the motor in fewer than 20 ms. This allowed attenuating centimetre-deep cuts made to a piece of meat by an unprotected rotor to mere superficial scratches.

Comparative study of thiopentone sodium, propofol, etomidate for anesthetic efficacy & effect on seizure duration in electroconvulsive therapy

Electroconvulsive treatment (ECT) is an entrenched mental treatment where seizures are electrically actuated in patients for restorative impacts. ECT can deliver extreme unsettling influences in the cardiovascular framework most generally a transient time of hypertension & changes in the pulse and a stamped increment in cerebral blood stream and intracranial weight. These hemodynamics changes might be adjusted utilizing different sedative medications. This investigation was attempted to think about the impacts of propofol, etomidate and thiopentone sodium utilized as IV sedative operators in changed ECT as respects, acceptance time & nature of sedation, adjustment of hemodynamics, seizure length & recuperation time.After authorization acquired from the moral board of trustees for the investigation, composed assent from the patient & family members was taken. This investigation was led in the division of anesthesiology at Civil Hospital, Ahmedabad, which remembered a sum of 90 patients for the 18-60 years age gathering.In our current investigation, we inferred that each of the three instigating operators had sure more than each other when the examination boundaries were individualized. Propofol had the upside of stable hemodynamic boundaries, smooth enlistment & fast recuperation in contrast with etomidate & thiopentone. Nonetheless, it was related with more limited span of seizure. The benefit of thiopentone sodium of having longer seizure length than propofol of having longer seizure span was brought about at the expense of a generally delayed recuperation period. The clear bit of leeway of a more extended seizure length with etomidate could be utilized for better clinical adequacy. Notwithstanding, it was related with myoclonic jerks during the cycle of acceptance. Further examinations ought to be planned to utilize a stage & mix of medications with the goal that the most ideal impacts of each medication can be sensibly utilized.