Enakshi Bhattacharya

Bio: Enakshi Bhattacharya is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Silicon & Surface micromachining. The author has an hindex of 14, co-authored 80 publications receiving 873 citations. Previous affiliations of Enakshi Bhattacharya include Indian Institutes of Technology & Tata Institute of Fundamental Research.

A monitored miniature dialysis apparatus with silicon nanoporous membrane

Abstract: Dialysis is a life-sustaining treatment for patients with end-stage kidney disease. Conventional hemodialysis done at hospitals is inaccessible to many patients, increases the load on the hospitals, and cause discomfort for older people. A portable self-monitored dialysis device can be of great relief for conventional, short-duration and nocturnal home-based dialysis. In our previous reports, functionalized silicon nanoporous membranes were shown to be efficient in uremic clearance. In the present study, pressure, temperature and bubble sensors were incorporated to develop a functional prototype with a connected system for real-time monitoring of the performance and progress of dialysis.

Space charge limited currents and the statistical shift in amorphous semiconductors

Abstract: In this paper we have shown that there is a correlation between statistical shift and space charge limited currents. We have shown that from a study of space charge limited currents it is possible to make an estimate of the coefficient of statistical shift without actually knowing the details of the distribution of gap states.

In-house SiN process development for integrated photonic applications

Abstract: Over the last decade, silicon nitride (SiN) based integrated photonics has become popular due to its CMOS com-patibility, low loss, wide spectral operation band and tolerance to high optical power. It has great potential in different application areas like quantum information processing, microwave photonics, spectroscopy, etc. However, the growth of an optical grade oxide layer (for bottom cladding) and subsequent deposition of SiN device layer on the surface of a handle silicon wafer are the most important aspects for the realization of large- scale photonic integrated circuits with an acceptable waveguide losses and fabrication yields. In this paper, we report the in- house technology development of SiN waveguide devices starting from a 4- inch silicon wafer. Both the thermally grown buried oxide (BOX) and the LPCVD deposited SiN device layer show excellent uniformities in terms of their thickness $(1900\pm 20nm, 400\pm 4nm$, respectively) as well as refractive indices $(n_{SiO_{2}}= 1.45\pm 0.001, n_{SiN}=2.024\pm 0.003$ at $\lambda\sim 1.55\mu m)$ across the full wafer. We have discussed the design and characterization of the grating coupler, single mode waveguides operating at $\lambda\sim 1.55\mu m$ and their fabrication flow as well. The fabricated single mode waveguides (TE polarized) with input/output grating couplers exhibit a 3-dB bandwidth of $\sim 50nm$ with a peak transmission efficiency at $\lambda\sim 1570nm$. The SiN waveguides fabricated out of in-house processed SiN wafer exhibit reasonable third order non-linearity; confirmed by stimulated four wave mixing experiment.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Electrostatic pull-in instability in MEMS/NEMS: A review

Abstract: Pull-in instability as an inherently nonlinear and crucial effect continues to become increasingly important for the design of electrostatic MEMS and NEMS devices and ever more interesting scientifically. This review reports not only the overview of the pull-in phenomenon in electrostatically actuated MEMS and NEMS devices, but also the physical principles that have enabled fundamental insights into the pull-in instability as well as pull-in induced failures. Pull-in governing equations and conditions to characterize and predict the static, dynamic and resonant pull-in behaviors are summarized. Specifically, we have described and discussed on various state-of-the-art approaches for extending the travel range, controlling the pull-in instability and further enhancing the performance of MEMS and NEMS devices with electrostatic actuation and sensing. A number of recent activities and achievements methods for control of torsional electrostatic micromirrors are introduced. The on-going development in pull-in applications that are being used to develop a fundamental understanding of pull-in instability from negative to positive influences is included and highlighted. Future research trends and challenges are further outlined.

Textbook of biochemistry with clinical correlations

Abstract: Textbook of biochemistry with clinical correlations , 4th edn TM Devlin, ed pp xvii + 1186, illustrated Wiley-Liss, New York, 1997 £2995, hardback This beautifully illustrated and well-written book, with an impressive array of authors, is aimed at both undergraduate and postgraduate level As the editor states in the preface, it is not intended to be a compendium of biochemistry but rather emphasises the biochemistry of mammalian cells The first 22 chapters cover …