Feasibility of a Gelatin Temperature Sensor Based on Electrical Capacitance

Abstract

The innovative use of gelatin as a temperature sensor based on capacitance was studied at a temperature range normally used for meat cooking (20–80 °C). Interdigital electrodes coated by gelatin solution and two sensors of different thicknesses (38 and 125 µm) were studied between 300 MHz and 900 MHz. At 38 µm, the capacitance was adequately measured, but for 125 µm the slope capacitance versus temperature curve decreased before 900 MHz due to the electrothermal breakdown between 60 °C and 80 °C. Thus, for 125 µm, the capacitance was studied applying 600 MHz. Sensitivity at 38 µm at 868 MHz (0.045 pF/°C) was lower than 125 µm at 600 MHz (0.14 pF/°C), influencing the results in the simulation (temperature range versus time) of meat cooking; at 125 µm, the sensitivity was greater, mainly during chilling steps. The potential of gelatin as a temperature sensor was demonstrated, and a balance between thickness and frequency should be considered to increase the sensitivity.

Electrochemical Performance of Biopolymer-Based Hydrogel Electrolyte for Supercapacitors with Eco-Friendly Binders

“…For all the devices fabricated, the resulting value of the frequency shift decreases in a range between 30° and 44.5°, confirming the presence of a major pseudocapacitive contribution arising from the diffusion [ 27 ]. This behaviour can be related to the presence of a large number of polar functional groups within the gelatin that can be influenced by the electric field polarization [ 61 ]. Moreover, the pseudocapacitance behaviour observed at the electrode interface is also influenced by the binders that contain atoms (such as Na in casein and CMC) and functional groups (e.g., carboxyl, hydroxyl and amino) that interact with the activated carbon at the interface with the gel electrolyte [ 32 ].…”

Recent Progress of Self‐Powered Sensing Systems for Wearable Electronics

“…However, many challenges still remain for the wearable temperature sensing application: (1) interferences form the external environment, such as various gases, different humidity and light, (2) accurate and stable detection of temperature under human motion, and (3) achievement of high‐resolution temperature distribution using sensor array. To realize the above three requirements, sensors are at least needed to be realized on a flexible/stretchable substrate as an essential or constituent element in practical healthcare and medical applications . Lee and co‐workers developed a stretchable and transparent temperature sensor that can be easily attached to human skin or objects ( Figure a,b) .…”

Carbon black nanoparticles modified gelatin composite-based thin film for rapid-response humidity sensing

“…Its sensitivity and response time are around 0.048/% RH and 20 s, respectively. Gelatin (GE), an inexpensive and easily achievable material, can be applied as an effective sensing polymer for physical quantities' measurement, such as strain [22], stress [23], temperature [24], or mechanical movement [25]. For higher sensitivity and specificity, GE has been applied for surface modification of commercial microcantilevers [26].…”