Printed Wheatstone bridge with embedded polymer based piezoresistive sensors for strain sensing applications

Abstract

Printed sensors find an increasing interest essentially due to their characteristics of flexibility and low cost per unit area. In this work a screen printed Wheatstone bridge is presented, suitable for strain sensing applications. A piezoresistive ink composite based on biocompatible thermoplastic elastomer styrene-ethylene/butylene-styrene (SEBS) as matrix and multi-walled carbon nanotubes (MWCNT) as nanofillers was used as a piezoresistive sensing material. Different deposition techniques, such as, screen printing, spray painting and drop casting were evaluated in order to optimize the resistance variation related to the piezoresistive effect. Several Wheatstone bridges with one and two sensors were designed to obtain an output sensitivity as a function of the strain submitted to the sensors. Further, different sensor geometries were evaluated to maximize the strain output sensitivity. Electro-mechanical bending tests showed a good linearity and a sensitivity up to 18 mV/V in the all screen printed half Wheatstone bridge output with two MWCNT/SEBS sensors.

Environmentally Friendly Graphene‐Based Conductive Inks for Multitouch Capacitive Sensing Surfaces

“…[ 27 ] This noise can be neutralized through signal processing techniques, but the most consensual approach to reduce is to take advantage of differential analog signal processing, eliminating similar signals in the grid. [ 27,28 ] As a result, the output signal will be just the desirable differential component for the conversion. [ 29 ]…”

Highly Sensitive Piezoresistive Sensors Based on a Voltage Divider Circuit With TFTs for Ultra-Low Pressure Detection

“…Thin film transistors (TFTs) technology has been successfully used in large-scale integration, such as display panels [14], sensor devices [15] and so on, owing to its advantages of small-size, low-cost and amplification effect. It approves that the gate voltage and the source-drain current are used as the basic sensor signals extracted from the TFTs [16]. In the saturated region of TFT, the slight pressure change can even lead to the obvious magnitude change of current.…”

Printed Strain Gauge on 3D and Low-Melting Point Plastic Surface by Aerosol Jet Printing and Photonic Curing

“…Since a large variety of materials can be adopted, PE can overcome some limitations of the silicon-based electronics, especially in flexible electronic applications such as flexible electrodes for healthcare applications [9], wearable devices [12], or bioelectronic applications by using organic semiconductors [13] which better match mechanical and conduction properties of biotic tissue. Furthermore, since it offers low-cost processes for large areas and flexible applications [14] with minimum material wastage and reduced time consumption [15], PE attracts a growing interest in producing light devices such as flexible displays, electrodes, sensors, antennas, radio-frequency identification tags, and solar cells [16]. In the field of the Internet of Things (IoT), where everyday objects are equipped with sensing, computing, and storage capabilities that communicate information [17], PE promotes the development of customized IoT devices equipped with fully or hybrid advanced printed electronics, of arbitrarily complex pattern, and tailor-made for a specific application [12].…”