Micro- and nano air vehicles are defined as “extremely small and ultra-lightweight air vehicle systems” with a maximum wingspan length of 15 cm and a weight less than 20 grams. Here, we provide a review of the current state of the art and identify the challenges of design and fabrication. Different configurations are evaluated, such as fixed wings, rotary wings, and flapping wings. The main advantages and drawbacks for each typology are identified and discussed. Special attention is given to rotary-wing vehicles (helicopter concept); including a review of their main structures, such as the airframe, energy storage, controls, and communications systems. In addition, a review of relevant sensors is also included. Examples of existing and future systems are also included. Micro- and nano-vehicles with rotary wings and rechargeable batteries are dominating. The flight times of current systems are typically around 1 hour or less due to the limited energy storage capabilities of the used rechargeable batteries. Fuel cells and ultra capacitors are promising alternative energy supply technologies for the future. Technology improvements, mainly based on micro- and nanotechnologies, are expected to continue in an evolutionary way to improve the capabilities of future micro- and nano air vehicles, giving improved flight times and payload capabilities.
Purpose
– Unmanned vehicles flight is controlled by embedded circuits in the aircraft, under the remote control of a pilot on the ground. This circuit, called autopilot, represents one of the key elements inside the vehicles. The authors developed one of the smallest autopilot, specifically designed for low-weight low-power applications. The paper aims to discuss these issues.
Design/methodology/approach
– The system is based on STM32 ARM Cortex M3 microcontroller. It includes an onboard 9 DOF IMU (MPU9150) and a 2.4 GHz wireless transceiver (nRF24L01+).
Findings
– The embedded lightweight kinematic autopilot (ELKA) can pilot up to eight servomotors, and can be used to monitor more than 100 sensors. The final assembled board is 28×21 mm2 and weighs around 1.2 grams (battery excluded), and has successfully passed initial functionality tests.
Originality/value
– The authors presented the design, fabrication and initial tests of a lightweight kinematic autopilot (ELKA board version 1.0). The system has been designed in order to upgrade the state-of-art capability in sensing and processing over a previous autopilot (GINA), which is of similar weight and size. The small size (28×21 mm2) and the lightweight (around 1.2 grams) make ELKA one of the smallest autopilot in the world.
AbstractÀNowadays, in many applications, limited space and weight budgets are two important variables that the designer should handle. Many fields such as aerospace or portable electronics require extremely small interconnection solutions, which go behind standard cables and connectors. To overcome this problem, we present the design, fabrication, and testing of an ultra-low-weight spacer for PCB to PCB interconnections. The novelty of this work is that this paper presents an easy and reliable solution capable of creating strong electrical and mechanical bonding at the same time. The extremely limited weight of the spacer (74 mg) and the relatively small dimension (5 mm 3 5 mm) make this system a possible solution for applications requiring minimal space and weight.
In this paper we will present the analytical modeling of two different microphone membranes (one square and one circular) fabricated using the MultiMEMS process at Sensonor in Norway. In particular we built up a mathematical model of the pressurebehavior inside the cavity, when an external pressure is applied. The time constant of the exponential solution, gave us the possibility to estimate the minimum working frequencies of these devices. We compared the results that we found with both the mechanical resonance estimates from FEM models and the initial measurements of the devices presented in [.
We present the design, fabrication and characterization of an application specific triaxial accelerometer for post-surgery heart monitoring. The accelerometer chip is designed as a 2 9 4 9 1.2 mm 3 chip with nominal acceleration range of ±4 g and frequencies below 50 Hz. It has been fabricated using a multiproject wafer service with an additional deep reactive ion etching process to obtain controlled etch-through of membranes of 3, 23 and 400 lm thicknesses simultaneously. The novelty of the work presented here is the bulk micromachining technique using both deep reactive dry etching and alkali-based anisotropic wet etching of single crystal (100) silicon wafers used to obtain a space efficient design. Proof of concept is demonstrated with preliminary testing, with an acceleration sensitivity of *0.04 mv/V/g for out of plane (z axis) acceleration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.