A hydrogel actuated microsystem employed in controlling the opening-closing states of a microvalve is described. This microsystem consists of a flexible silicone rubber diaphragm with an attached silicon boss and a cantilever beam. Swelling of the hydrogel forces the bossed membrane and consequently the cantilever beam to be deflected. Simulations were done by FEM analysis and the results show enough deflections to open the valve and let the fluid flow through the microvalve.
Research on microneedles has been increasing rapidly to overcome the drawbacks of hypodermic needle which can results in painful injection, tissue damage and uncontrollable delivery rate. This paper presents process characterization of wet isotropic etching for solid microneedles array development. Work has been carried out to investigate the isotropic etching behavior in 17 different compositions of HNA solution. The experimental responses of vertical etch rate and lateral etch rate are presented. Resulting surface profiles from various HNA compositions are also reported. The etching properties will be applied to develop recipe to fabricate the optimum solid microneedles.
This paper reports the fabrication of a quantum dots (QD)-organics hybrids light-emitting diode (LED) for potential light sources. Organic light emitting diode (OLED) have become a focus of attention since past decades for potential light sources in a flat panel displays applications. Despite their intriguing performance in producing rich-color light emission, they still faced several critical defects, such as relatively low-brightness, low-chemical and photostability and short lifetime. Here, we demonstrate a novel system for the production of pure-color light emission with exceptionally high brightness by utilizing quantum dots that are hybridizing with light emitting organic materials, as an active material in light - emitting diode devices. Organic-quantum dots hybrid LED devices was fabricated by sandwiching the quantum dots monolayer between the electron transport layer (ETL) and hole transport layer (HTL) in a conventional OLED structure (ITO/ETL/QD/HTL/Al). Quantum dots of CdSe (ZnS) core-shell structure were function as the emitting layer. The ETL and HTL were poly(vinyl carbazol), PVK and tris(8-quinolinolato)aluminum(III), Alq3; respectively. The current-voltage (I-V) characterization on the device was found that the hybrid LED exhibited a strong blue emission under a relatively low bias voltage, of which their turn-on voltage was as low as 5.0 V.
SAMEER has recently setup an infrastructure to 'Pigtail and package Laser diodes' using optical epoxy and laser weld techniques. Few Laser diodes have been packaged using 'Fiber Alignment and Laser Weld System (FALWS)' in Butterfly and TO-CAN packages. The high power laser diode packaging involves good thermal management and post-weld shift challenges, and it is being experimentally verified with theoretical simulation. The Laser Diode packaging followed by reliability test as per Telcordia standard is the current technical challenges ahead.
Measurement of the foot and shoe interface pressure underpins a number of important applications. Abnormal pressure may indicate instability in gait, risks of diabetic ulceration and many other biomedical and sports applications. As the current foot pressure sensors in the market exhibit many limitations, a new sensor design based on the more promising MEMS technology was therefore explored. As such, this paper reports the analysis and optimization of a MEMS pressure sensor for foot pressure measurement. The pressure sensor had a high linearity output with pressure span of more than 2-MPa. This characteristic indicates excellent potential for a wide spectrum of biomechanical activities.
