Jothiramalingam Kulothungan

Dr. Jothiramalingam Kulothungan

Japan Advanced Institute of Science and Technology

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
15 August 2016 in Micromachines
Verified
Journal Article
Open access
PDF file
JKJothiramalingam Kulothungan
Jothiramalingam Kulothungan
MMManoharan Muruganathan
Manoharan Muruganathan
Hiroshi MizutaHiroshi Mizuta
Hiroshi Mizuta
In this paper, we report the finite element method (FEM) simulation of double-clamped graphene nanoelectromechanical (NEM) switches. Pull-in and pull-out characteristics are analyzed for graphene NEM switches with different dimensions and these are consistent with the experimental results. This numerical model is used to study the scaling nature of the graphene NEM switches. We show the possibility of achieving a pull-in voltage as low as 2 V for a 1.5-μm-long and 3-nm-thick nanocrystalline graphene beam NEM switch. In order to study the mechanical reliability of the graphene NEM switches, von Mises stress analysis is carried out. This analysis shows that a thinner graphene beam results in a lower von Mises stress. Moreover, a strong electrostatic force at the beam edges leads to a mechanical deflection at the edges larger than that around the center of the beam, which is consistent with the von Mises stress analysis.

31 July 2017 in Micromachines
Verified
Journal Article
Open access
PDF file
MZMohd Amir Zulkefli
Mohd Amir Zulkefli
MMMohd Ambri Mohamed
Mohd Ambri Mohamed
KSKim Siow
Kim Siow
BMBurhanuddin Yeop Majlis
Burhanuddin Yeop Majlis
JKJothiramalingam Kulothungan
Jothiramalingam Kulothungan
Hiroshi MizutaHiroshi Mizuta
Hiroshi Mizuta
The miniaturization trend leads to the development of a graphene based nanoelectromechanical (NEM) switch to fulfill the high demand in low power device applications. In this article, we highlight the finite element (FEM) simulation of the graphene-based NEM switches of fixed-fixed ends design with beam structures which are perforated and intact. Pull-in and pull-out characteristics are analyzed by using the FEM approach provided by IntelliSuite software, version 8.8.5.1. The FEM results are consistent with the published experimental data. This analysis shows the possibility of achieving a low pull-in voltage that is below 2 V for a ratio below 15:0.03:0.7 value for the graphene beam length, thickness, and air gap thickness, respectively. The introduction of perforation in the graphene beam-based NEM switch further achieved the pull-in voltage as low as 1.5 V for a 250 nm hole length, 100 nm distance between each hole, and 12-number of hole column. Then, a von Mises stress analysis is conducted to investigate the mechanical stability of the intact and perforated graphene-based NEM switch. This analysis shows that a longer and thinner graphene beam reduced the von Mises stress. The introduction of perforation concept further reduced the von Mises stress at the graphene beam end and the beam center by approximately ~20–35% and ~10–20%, respectively. These theoretical results, performed by FEM simulation, are expected to expedite improvements in the working parameter and dimension for low voltage and better mechanical stability operation of graphene-based NEM switch device fabrication.

1 November 2019 in Carbon
Verified
Journal Article
Closed access
JKJothiramalingam Kulothungan
Jothiramalingam Kulothungan
MMManoharan Muruganathan
Manoharan Muruganathan
HMHiroshi Mizuta
Hiroshi Mizuta

1 October 2016
Verified
Conference Paper
Closed access
HMHiroshi Mizuta
Hiroshi Mizuta
AHAhmed Hammam
Ahmed Hammam
JKJothiramalingam Kulothungan
Jothiramalingam Kulothungan
SSShunei Suzuki
Shunei Suzuki
MSMarek Schmidt
Marek Schmidt
MMManoharan Muruganathan
Manoharan Muruganathan
Graphene possesses remarkable electronic and mechanical properties and provides a promising platform to explore future nanoelectronic and nano electro-mechanical (NEM) devices for challenging applications. This paper presents a brief overview of our recent attempts of developing novel graphene-based nanoscale devices. We first present state-of-the-art fabrication technology for sub-10-nm graphene nanostructures using atomic-size focused helium ion beam. Secondly graphene-based tunnel FETs (GTFETs) are discussed, which are expected to achieve advanced switching characteristics in comparison with conventional MOSFETs. We then describe graphene NEM (GNEM) switches with low voltage switching operation and GNEM chemical gas sensors with single-molecular-level detection limit.

17 October 2018 in Microsystem Technologies
Verified
Journal Article
Closed access
PDF file
JKJothiramalingam Kulothungan
Jothiramalingam Kulothungan
MSMarek E. Schmidt
Marek E. Schmidt
MMMuruganathan Manoharan
Muruganathan Manoharan
AHAhmed M. M. Hammam
Ahmed M. M. Hammam
HMHiroshi Mizuta
Hiroshi Mizuta

18 December 2022 in Advanced Physics Research
Verified
Journal Article
Open access
JKJothiramalingam Kulothungan
Jothiramalingam Kulothungan
KKKarthi Kandhasamy
Karthi Kandhasamy
Nano‐electromechanical (NEM) contact switches are extensively studied to suppress the limitations of conventional complementary metal‐oxide‐semiconductor (CMOS) transistors. The attributes of NEM contact switches includes reduced power consumption, reduced off‐state leakage current, and increased on‐state current and sub‐thermal switching. However, unacceptably high pull‐in voltage and low contact lifetime posed a significant challenge for the use of NEM contact switches in energy efficient CMOS applications. Here, graphene‐based electro‐statically actuated NEM contact switches with ultra‐low pull‐in voltage and significant improvement in the contact lifetime are demonstrated. This is achieved by using the graphene on gold electrode as a contact material. The graphene NEM contact switches with graphene as a contact material exhibit an ultra‐low pull‐in voltage of < 0.5 V and high contact lifetime of more than 1.5× 106 cycles. The switches also show an excellent switching performance with high on/off ratio of ≈108, an extremely low off‐state current of ≈100 fA, and small hysteresis window of < 0.1 V.