Development of Sandwich Construction Rules

Abstract In this contribution a micromachined open/closed valve is presented which is driven by a conventionally manufactured bistable electromagnetic actuator. Basically the micromachined valve part, 7 × 7 × 1 mm3 in dimension, is a sandwich construction of two KOH etched wafers with a specially formulated silicone rubber layer in between. This rubber sheet forms a flexible flow path, which can be open and closed to control a fluid flow. In order to provide a large stroke of about 200 μm, a precision-engineered bi-stable electromagnetic actuator was selected. This actuator consists of a spring-biased armature that can move up and down in a magnetically soft iron housing, incorporating a permanent magnet and a coil. It will be shown that this combination of micromachined and precision-engineered components provides the required low dead volume on the one hand and a large actuator stroke on the other. Another benefit of the application of a bi-stable actuator is the fact that only energy is needed in order to switch between the open and closed state. Moreover, the large stroke makes the valve particle tolerant thus allowing media like cell suspensions and whole blood.

Download Full-text

Notes on Sandwich Construction

Aircraft Engineering and Aerospace Technology ◽

10.1108/eb031775 ◽

1949 ◽

Vol 21 (6) ◽

pp. 196-196 ◽

Cited By ~ 2

Author(s):

J. Lockwood Taylor

Keyword(s):

Sandwich Construction

Download Full-text

Preparation and Characterization of Glycyrrhizin-Graphene Hybrid Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.531.145 ◽

2012 ◽

Vol 531 ◽

pp. 145-148

Author(s):

Zong Hua Wang ◽

Yan Li Gao ◽

Jian Fei Xia ◽

Fei Fei Zhang ◽

Yan Zhi Xia ◽

...

Keyword(s):

Electron Transfer ◽

Hybrid Materials ◽

Model Compound ◽

Carbon Electrode ◽

The Novel ◽

Electron Transfer Process ◽

Efficient Energy ◽

Sandwich Construction ◽

Photo Induced Electron Transfer

A glycyrrhizin decorated graphene hybrid materials (GL-G) was synthesized, which is a layer-to-layer sandwich construction. The results of characterization indicate that a photo induced electron transfer process or efficient energy transferring along the GL-G interface. Furthermore, the as-made hybrid material was used as a modifier of the glassy carbon electrode to construct a sensor (GL-G/GCE). Using p-nitrophenol as a model compound, the novel sensor demonstrated a highly enhanced electrochemical activity for it. The peak current of p-nitrophenol was significantly improved at the sensor.

Download Full-text

Face Wrinkling and Core Strength in Sandwich Construction

Journal of the Royal Aeronautical Society ◽

10.1017/s036839310007231x ◽

1960 ◽

Vol 64 (591) ◽

pp. 164-167 ◽

Cited By ~ 10

Author(s):

S. Yusuff

Keyword(s):

High Stress ◽

Core Layer ◽

High Strength ◽

Bending Rigidity ◽

Core Strength ◽

Surface Smoothness ◽

Lightweight Material ◽

The Core ◽

Sandwich Construction ◽

Strength Material

The effect of initial waviness on the wrinkling of faces in sandwich construction is studied. Formulae are derived to determine the failing stress when the faces wrinkle due to failure of the core in tension, compression or shear. The importance of core strength requirements in maintaining surface smoothness is noted. A comparison of theory with experiments is made, and the agreement between the two is found to be reasonably good.A sandwich construction consists of two thin face layers of high-strength material and a thick core layer of lightweight material. The function of the core is twofold. Firstly, it increases the bending rigidity of the faces and second, it stabilises them so that they will not wrinkle until high stress is reached.

Download Full-text

Sandwich Structures for Naval Ships: Design and Experience

10.1115/imece2000-2019 ◽

2000 ◽

Author(s):

Karl-Axel Olsson

Keyword(s):

Lightweight Design ◽

Weight Ratio ◽

Point Of View ◽

Economic Point ◽

Plastic Foams ◽

Reinforced Plastics ◽

Sandwich Construction ◽

Glass Fibre Reinforced Plastic ◽

Glass Fibre Reinforced ◽

Common Face

Abstract In Sweden we have a long experience with different types of vehicles and ships in sandwich construction, especially Navy ships such as minesweepers, mine-counter-measure-vessels and corvettes. GRP (Glass fibre Reinforced Plastic) and FRP (Fibre Reinforced Plastics) have been the most common face materials, but metallic materials such as Al-alloys, coated carbon steel and stainless steel have also been used. Core materials have usually been cellular plastic foams of cross-linked PVC (Polyvinyl-chloride), but also extruded PS (Poly-styrene), PUR (Poly-urethane), PEI (Poly-ether-imide) and PMI (Poly-methacryl-imide). Different continuous and discontinuous manufacturing processes have been used. Vacuum assisted infusion has been introduced recently, because it is a closed process, gives high fibre content and a good quality of the laminates. Sandwich design has mainly been used in the transportation area, where lightweight design is needed to give higher performance and load bearing capacity. The use of sandwich construction will give high stiffness- and strength-to weight ratio. This is usually not enough from an economic point of view to justify the introduction of sandwich construction, but other integrated functions must be considered, i.e. insulation, energy consumption, damping, fewer components, lower manufacturing costs, low maintenance, signature effects (military) etc.

Download Full-text