Inkjet-Deposited Single-Wall Carbon Nanotube Micropatterns on Stretchable PDMS-Ag Substrate–Electrode Structures for Piezoresistive Strain Sensing

Abstract

Printed piezoresistive strain sensors based on stretchable roll-to-roll screen-printed silver electrodes on polydimethylsiloxane substrates and inkjet-deposited single-wall carbon nanotube micropatterns are demonstrated in this work. With the optimization of surface wetting and inkjet printing parameters, well-defined microscopic line patterns of the nanotubes with a sheet resistance of <100 Ω/□ could be deposited between stretchable Ag electrodes on the plasma-treated substrate. The developed stretchable devices are highly sensitive to tensile strain with a gauge factor of up to 400 and a pressure sensitivity of ∼0.09 Pa –1 , respond to bending down to a radius of 1.5 mm, and are suitable for mounting on the skin to monitor and resolve various movements of the human body such as cardiac cycle, breathing, and finger flexing. This study indicates that inkjet deposition of nanomaterials can complement well other printing technologies to produce flexible and stretchable devices in a versatile manner.

An Atlas for the Inkjet Printing of Large-Area Tactile Sensors

“…Using inkjet printing technology, silver, single-wall carbon nanotubes (SwCNT) and graphene are conductive materials used in many works [ 101 , 132 , 139 , 165 , 166 ]. The contribution of inkjet printing for the manufacturing of these kind of sensors is to introduce a cheaper alternative aiming to minimize the complexity without compromising the quality and sensing performance for the target application.…”

“…Tactile sensors can also be printed onto the glove to measure the pressure exerted by the fingers. Ervasti et al [ 166 ] proposed a stretchable inkjet-printed piezoresistive tactile sensor with high sensitivity to bending for finger joints flexion measurements.…”

“…Inkjet printing technology emerged in this domain for its potential to manufacture highly integrated and custumized sensors, as well as for the possibility of designing small devices. The development of tactile sensors for soft robots evolves with the investigation and development of inkjet-printed electronics solutions for deformable and stretchable materials [ 166 , 187 , 188 ].…”

“…By making electronic devices flexible, it is possible to significantly enhance their healthcare applications in the emerging Internet of Things (IoT) [ 190 ]. Furthermore, wearable electronic skin (e-skin) devices with skin-like properties can adhere conformally to the skin and interface with the human body to mimic the human somatosensory system and enable convenient and non-invasive tracking of physical and biochemical signals [ 166 , 185 , 189 , 191 , 192 , 193 ].…”

Bioplastics and Carbon-Based Sustainable Materials, Components, and Devices: Toward Green Electronics

“…For instance, carbon nanotubes can be grown from alcohols or oils (or from virtually any organic compounds) in the presence of a Fe, Ni, or Co catalyst . Graphene and graphene oxide may be produced by exfoliation of graphite as well as by chemical vapor deposition from methane (and also from other natural organics) on Ni and Cu surfaces, − and pyrolytic carbon particles can be produced from abundant lignin and celluloses. − Although the electrical conductivity of carbon-based materials is also lower than that of metals, it is sufficiently high to replace ITO in transparent conductive films (solar cells, touch panels, and sensors) − to substitute metal electrodes (capacitors, touch sensors) and , to find use as piezoresistive elements on polymers as well as fillers in conductive composites with polymers (electromagnetic interference shielding, piezoresistive sensors), − which justifies and prompts their utilization in future electronics.…”