Graphite nanobelts characterization and application for blood pulse sensing

Abstract

In this work, graphite nanobelts-based films as a promising material for applications in flexible blood pulse sensors with low power consumption are studied. A modified Langmuir Blodgett method used here for the sensor fabrication, is a reliable, simple and scalable technique allowing for controlled deposition of conducting films with desired electrical properties. The nanobelts, deposited over oxidized silicon or onto flexible polydimethylsiloxane substrates, were morphologically and electrically characterized. The response of the sensors to blood pulses measured on wrists and necks of two different persons (a male and a female) and the ways of the sensor response optimization are discussed.

Combined Pressure Sensor With Enhanced Dynamic Range Based on Thin Films of Nanotubes and Graphite Nanobelts

“…As nanotubes and nanobelts films demonstrate the ability to detect pressure impact in distinct pressure regions (S 1 for nanotubes and S 2 -S 3 for GNBs), these films can be integrated into one device and can act as combined sensitive elements in pressure sensors ( Figure 5) with enhanced dynamic range and low power consumption, about 1 mW (estimated from Figure 2E). Taking into account the results of physiological signal-detecting tests obtained in our previous work in sensors contained only GNBs sensitive layer with reduced sensitivity and dynamic range (Alaferdov et al, 2017), the combined sensors developed in the current research can be employed for monitoring of cardiorespiratory signals, blood circulation in arteries, and breathing, with performance comparable with best results available in literature (Wang et al, 2014;Park et al, 2018) and MWCNTs (Jian et al, 2017).…”

“…Thin films (Wang et al, 2014;Park et al, 2018) of nanotubes demonstrate high sensitivity but relatively low dynamic range and higher limit of sensing. Sensors based on multiplayer graphene or nanographite (Alaferdov et al, 2017) can be used for monitoring of higher pressures. In this way, usually one type of graphite nanostructure is used for pressure sensor fabrication.…”