High-range noise immune supersensitive graphene-electrolyte capacitive strain sensor for biomedical applications

Shirhatti, Vijay and Kedambaimoole, Vaishakh and Nuthalapati, Suresh and Neella, Nagarjuna and Nayak, M M and Rajanna, K (2019) High-range noise immune supersensitive graphene-electrolyte capacitive strain sensor for biomedical applications. In: NANOTECHNOLOGY, 30 (47).

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Abstract

This paper presents development and performance assessment of an innovative and a highly potent graphene-electrolyte capacitive sensor (GECS) based on the supercapacitor model. Although graphene has been widely researched and adapted in supercapacitors as electrode material, this combination has not been applied in sensor technology. A low base capacitance, generally the impeding factor in capacitive sensors, is addressed by incorporating electric double layer capacitance in GECS, and a million-fold increase in base capacitance is achieved. The high base capacitance (similar to 22.0 mu F) promises to solve many inherent issues pertaining to capacitive sensors. GECS is fabricated by using thermally reduced microwave exfoliated graphene oxide material to form interdigitated electrodes coated with solid-state electrolyte which forms the double layer capacitance. The capacitance response of GECS on subjecting to strain is examined and an enormous operating range (similar to 300 nF) is seen, which is the salient feature of this sensor. The GECS showed an impressive device sensitivity of 11.24 nF kPa-1 and good immunity towards noise i.e. lead capacitance and stray capacitance. Two regimes of operation are identified based on the procedure of device fabrication. The device can be applied to varied applications and one such biomedical application of breath pattern monitoring is demonstrated.

Item Type:	Journal Article
Publication:	NANOTECHNOLOGY
Publisher:	IOP PUBLISHING LTD
Additional Information:	copyright for this article belongs to IOP PUBLISHING LTD
Keywords:	graphene; strain sensor; base capacitance; supercapacitor; gel electrolyte
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	04 Nov 2019 06:42
Last Modified:	04 Nov 2019 06:42
URI:	http://eprints.iisc.ac.in/id/eprint/63664

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