Highly Sensitive Temperature Sensor: Ligand‐Treated Ag Nanocrystal Thin Films on PDMS with Thermal Expansion Strategy

Abstract

Highly sensitive temperature sensors are designed by exploiting the interparticle distance-dependent transport mechanism in nanocrystal (NC) thin films based on a thermal expansion strategy. The effect of ligands on the electronic, thermal, mechanical, and charge transport properties of silver (Ag) NC thin films on thermal expandable substrates of poly(dimethylsiloxane) (PDMS) is investigated. While inorganic ligand-treated Ag NC thin films exhibit a low temperature coefficient of resistance (TCR), organic ligandtreated films exhibit extremely high TCR up to 0.5 K −1 , which is the highest TCR exhibited among nanomaterial-based temperature sensors to the best of the authors' knowledge. Structural and electronic characterizations, as well as finite element method simulation and transport modeling are conducted to determine the origin of this behavior. Finally, an all-solution based fabrication process is established to build Ag NC-based sensors and electrodes on PDMS to demonstrate their suitability as low-cost, high-performance attachable temperature sensors.

Black Phosphorus@Laser‐Engraved Graphene Heterostructure‐Based Temperature–Strain Hybridized Sensor for Electronic‐Skin Applications

“…[ 35 ] An increase in resistance of the functional material upon a temperature rise changes transport/scattering behavior and the material geometry depending upon the substrate materials and their coefficient of thermal expansion (CTE) (Figure S10, Supporting Information). The mismatch in CTE between sensing and substrate materials causes interparticle‐dependent transport mechanisms in the thin films, leading to a high‐temperature coefficient of resistance (TCR), [ 34 ] as will be discussed later. A comparison of the initial resistance of the composite material before and after SEBS encapsulation is depicted in Figure 3c.…”

Material Design and Fabrication Strategies for Stretchable Metallic Nanocomposites

“…Other than electrophysiological signal sensing, the nanocomposite electrode can be also applied to measure other various signals from the human body such as the human motion (strain), body temperature, and pressure changes. Such sensors using the stretchable metallic nanocomposite have many advantages compared to the conventional nonstretchable sensors since they can measure signals on the skin or clothing with high reliability, stability, and durability, as well as minimal discomfort to the user .…”

Simultaneously Optimize the Response Speed and Sensitivity of Low Dimension Conductive Polymers for Epidermal Temperature Sensing Applications

“…Besides, the electron transport efficiency within the 1D nanowire is improved as well. Other nanomaterials-based resistive temperature sensors also have showed such advantages of nanomaterials in temperature detecting (Joh et al, 2018;Sehrawat et al, 2018;Bang et al, 2019;Cui et al, 2019). However, reducing the materials dimension will not influence the deformation ratio of the PSS boundaries, which is related to the amount of the water absorbed, thus the change of S/V ratio will not influence the thermal sensitivity of PEDOT: PSS.…”