A Multiparameter Pressure–Temperature–Humidity Sensor Based on Mixed Ionic–Electronic Cellulose Aerogels

Abstract

Pressure ( P ), temperature ( T ), and humidity ( H ) are physical key parameters of great relevance for various applications such as in distributed diagnostics, robotics, electronic skins, functional clothing, and many other Internet‐of‐Things (IoT) solutions. Previous studies on monitoring and recording these three parameters have focused on the integration of three individual single‐parameter sensors into an electronic circuit, also comprising dedicated sense amplifiers, signal processing, and communication interfaces. To limit complexity in, e.g., multifunctional IoT systems, and thus reducing the manufacturing costs of such sensing/communication outposts, it is desirable to achieve one single‐sensor device that simultaneously or consecutively measures P – T – H without cross‐talks in the sensing functionality. Herein, a novel organic mixed ion–electron conducting aerogel is reported, which can sense P – T – H with minimal cross‐talk between the measured parameters. The exclusive read‐out of the three individual parameters is performed electronically in one single device configuration and is enabled by the use of a novel strategy that combines electronic and ionic Seebeck effect along with mixed ion–electron conduction in an elastic aerogel. The findings promise for multipurpose IoT technology with reduced complexity and production costs, features that are highly anticipated in distributed diagnostics, monitoring, safety, and security applications.

Ambient‐Dried, 3D‐Printable and Electrically Conducting Cellulose Nanofiber Aerogels by Inclusion of Functional Polymers

“…Conducting aerogels have historically been used in numerous sensing applications as their electrical conductivity is generally sensitive to external stresses. Depending on the structure and chemical nature of the aerogels, they can be used to measure physical quantities such as temperature, mechanical stress, humidity, and the presence of specific gases …”

The Molecular Weight Dependence of Thermoelectric Properties of Poly (3-Hexylthiophene)

“…large power generation is not required, but being lightweight and flexible are paramount [7][8][9]. The performance of thermoelectric materials depends on the dimensionless thermoelectric figure of merit (ZT), which is defined as ZT = S 2 σT/k, where σ (S/m), k (W/mK), S (V/K), and T (K) are the electrical conductivity, the thermal conductivity, the Seebeck coefficient, and the absolute temperature, respectively.…”

Flexible 3D Architectured Piezo/Thermoelectric Bimodal Tactile Sensor Array for E‐Skin Application

“…The response speed of temperature sensing function is shown in Figure 2c, with an instant response time 0.37 s and fast recover time 0.93 s, which is superior to the TE-based temperature sensor in planar structure. [34,[43][44][45] The mechanical reliability of the sensor is tested as demonstrated in Figure 2d. At a bending radius of 10 mm, after bending 3000 times, the internal impedance of the thermoelectric module shows little increase (less than 10%); further, V versus ΔT curves measured after cyclic bending 3000, 3500, and 4000 times are shown in Figure S5 (Supporting Information), presenting little decline in sensitivity.…”