Flexible Ecoflex<sup>®</sup>/Graphene Nanoplatelet Foams for Highly Sensitive Low-Pressure Sensors

The high demand for multifunctional devices for smart clothing applications, human motion detection, soft robotics, and artificial electronic skins has encouraged researchers to develop new high-performance flexible sensors. In this work, we fabricated and tested new 3D squeezable Ecoflex<sup>...

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Bibliographic Details
Main Authors: Marco Fortunato, Irene Bellagamba, Alessio Tamburrano, Maria Sabrina Sarto
Format: Article
Language:English
Published: MDPI AG 2020-08-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/20/16/4406
Description
Summary:The high demand for multifunctional devices for smart clothing applications, human motion detection, soft robotics, and artificial electronic skins has encouraged researchers to develop new high-performance flexible sensors. In this work, we fabricated and tested new 3D squeezable Ecoflex<sup>®</sup> open cell foams loaded with different concentrations of graphene nanoplatelets (GNPs) in order to obtain lightweight, soft, and cost-effective piezoresistive sensors with high sensitivity in a low-pressure regime. We analyzed the morphology of the produced materials and characterized both the mechanical and piezoresistive response of samples through quasi-static cyclic compression tests. Results indicated that sensors infiltrated with 1 mg of ethanol/GNP solution with a GNP concentration of 3 mg/mL were more sensitive and stable compared to those infiltrated with the same amount of ethanol/GNP solution but with a lower GNP concentration. The electromechanical response of the sensors showed a negative piezoresistive behavior up to ~10 kPa and an opposite trend for the 10–40 kPa range. The sensors were particularly sensitive at very low deformations, thus obtaining a maximum sensitivity of 0.28 kPa<sup>−1</sup> for pressures lower than 10 kPa.
ISSN:1424-8220