Oxygen Sensing Properties of the WO3 Thick Films

This paper presents oxygen gas sensing properties of WO3 thick films. In this work, the WO3 thick films were prepared by standard screen-printing method. These films were characterized by X-ray diffraction (XRD) measurements and scanning electron microscopy (SEM). The oxygen gas sensing properties of these thick films were investigated at different operating temperatures and oxygen gas concentrations. The WO3 thick films exhibit excellent oxygen sensing properties with a maximum sensitivity of ~ 35.75 % at 350 oC in air atmosphere with fast response and recovery time

Fabrication of low cost thermomechanical analyser (TMA)

663-666Fabrication of low cost thermomechanical analyser(TMA) which is one of the versatile instrument required for determination of glass transition temperature (Tg) of polymer is reported. The cost reduction during fabrication is so extensive that the entire cost of the instrument can be as low as Rs 6000/- which makes it in fact, affordable for any college

Comparative analysis of electrical and hot water actuation of shape memory alloy spring using thermo-mechanical cycle test bench

The optimal design and analysis of hot water actuated shape memory alloy spring is presented. Smart materials exhibit special properties that make them a preferred choice for industrial applications in many branches of engineering. The serviceable properties of a Ni-Ti piece can be improved by altering the energy source. With hot water actuation, as the temperature reaches 70 °C - 90 °C, spring gets fully compressed for the first few cycles followed by loss in actuation. The actuation loss is then studied with different characterisation methods such as thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). With SEM results, it can be strongly recommended that the energy source is sufficient for actuation (not affecting too much the structure). Results observed from TGA shows high oxygen content at lower temperature, suggest the need of conducting experiments in inert atmosphere. For the validation of hot water actuation, comparative analysis between electrical and hot water actuation is done. Graph shows that, there is a good agreement between both the methods. In addition to this, the application of hot water actuation is some micro-devices like micro-valve, drug delivery, directional control valve, also in engine in place of thermostat valve etc

Dip pen nanolithography stamp tip

A simple and novel method for fabricating poly(dimethylsiloxane) (PDMS)-coated dip pen nanolithography (DPN) stamp tips was developed. These kinds of tips absorb chemicals (“inks”) easily and allow one to generate molecule-based patterns in a conventional DPN experiment. The generated patterns also can be imaged with the same DPN stamp tips. This method is a type of scanning probe contact printing but provides the ability to generate higher resolution structures than one can obtain with the conventional technique, which thus far has only enabled micron scale patterning. Sub-100 nm resolution patterning with 16-mercaptohexadecanoic acid (MHA) as an ink is demonstrated with these novel tips and is comparable to what one can obtain with a conventional ink-coated Si3N4 probe tip. Proof-of-concept is also demonstrated with 1-octadecanethiol (ODT), dendrimers and cystamine as inks

Angiokeratoma circumscriptum naeviforme with soft tissue hypertrophy and deep venous malformation: A variant of Klippel-Trenaunay syndrome?

Klippel-Trenaunay syndrome (KTS) is a cutaneous capillary malformation on a limb in association with soft tissue swelling with or without bony hypertrophy and atypical varicosity. The capillary malformation associated with KTS is port wine stain. Angiokeratoma circumscriptum naeviforme (ACN) is a congenital variant of angiokeratoma commonly present on the lower limb as a hyperkeratotic plaque. ACN is rarely associated with KTS. We report a case of ACN with soft tissue hypertrophy and deep venous malformation (possibly a variant of Klippel-Trenaunay) in a 4-year-old male child

Microstructure array on Si and SiOx generated by micro-contact printing, wet chemical etching and reactive ion etching

A method, combining micro-contact printing (μCP), wet chemical etching and reactive ion etching (RIE), is reported to fabricate microstructures on Si and SiOx. Positive and negative structures were generated based on different stamps used for μCP. The reproducibility of the obtained microstructures shows the methodology reported herein could be useful in Micro-Electro-Mechanical Systems (MEMS), optical and biological sensing applications