Dual Mode Strain–Temperature Sensor with High Stimuli Discriminability and Resolution for Smart Wearables

Abstract

Strain and temperature are important physiological parameters for health monitoring, providing access to the respiration state, movement of joints, and inflammation processes. The challenge for smart wearables is to unambiguously discriminate strain and temperature using a single sensor element assuring a high degree of sensor integration. Here, a dual-mode sensor with two electrodes and tubular mechanically heterogeneous structure enabling simultaneous sensing of strain and temperature without cross-talk is reported. The sensor structure consists of a thermocouple coiled around an elastic strain-to-magnetic induction conversion unit, revealing a giant magnetoelastic effect, and accommodating a magnetic amorphous wire. The thermocouple provides access to temperature and its coil structure allows to measure impedance changes caused by the applied strain. The dual-mode sensor also exhibits interference-free temperature sensing performance with high coefficient of 54.49 µV °C−1 , low strain and temperature detection limits of 0.05% and 0.1 °C, respectively. The use of these sensors in smart textiles to monitor continuously breathing, body movement, body temperature, and ambient temperature is demonstrated. The developed multifunctional wearable sensor is needed for applications in early disease prevention, health monitoring, and interactive electronics as well as for smart prosthetics and intelligent soft robotics.

Bioinspired Luminescent HOF‐Based Foam as Ultrafast and Ultrasensitive Pressure and Acoustic Bimodal Sensor for Human–Machine Interactive Object and Information Recognition

“…The pressing process can be treated as a tactile enhancement process, which leads to the luminescent H letter (Figure S30a,b, Supporting Information). The luminescent letters of A, E, G, H, I, J, L, N, O, P, and T were collected; their order numbers in 26 English letters are, respectively, 1, 5,7,8,9,10,12,14,15,16, and 20 as input information for BPNN3 (Figure S31 and Table S14, Supporting Information). When 8,5,1,12,20,and 8 were inputted in BPNN3, the output result was "Health".…”

“…The luminescent letters of A, E, G, H, I, J, L, N, O, P, and T were collected; their order numbers in 26 English letters are, respectively, 1, 5,7,8,9,10,12,14,15,16, and 20 as input information for BPNN3 (Figure S31 and Table S14, Supporting Information). When 8,5,1,12,20,and 8 were inputted in BPNN3, the output result was "Health". Relatively, the input information "16, 8, 15, 14, 5, 0", and "20, 15, 14, 7, 10, 9" can lead to the output results of "Phone" and "TongJi", respectively.…”

“…For example, a NP/CNC/CoAWs‐based bimodal strain–temperature sensor can simultaneously monitor the human exhale‐inhale process by strain sensing and body temperature by temperature sensing, which realizes the real‐time monitoring of human physiological signals. [ 8 ] A star‐nose‐like olfactory‐tactile bimodal sensor array can discriminate the hardness and odor of objects and recognize a series of objects with a high recognition rate by sensing the hardness and odor of objects. [ 9 ] The presence of BBSs has greatly integrated various sensing functions and effectively increased the dimension of detection.…”

Ti3C2Tx MXene-Based Multifunctional Tactile Sensors for Precisely Detecting and Distinguishing Temperature and Pressure Stimuli

“…Developing skin-like sensors capable of detecting multiple physical stimuli such as temperature changes and external pressure is crucial for advancing human–machine interaction, robotics, and healthcare. − Rather than assembling several single-function sensors to achieve multistimuli detection, creating a single multifunctional sensing device using a single active material represents a promising approach to meet the demands of high integration and miniaturization, although it is rather challenging . Recent advances demonstrate the possibility of simultaneous sensing temperature and pressure stimuli without interference by utilizing thermoelectric materials with both thermoelectric and piezoresistive properties and introducing innovative structural designs (e.g., creating cellular structures) to develop dual-mode sensors. − For effective temperature–pressure dual-mode sensing, an ideal thermoelectric material should have (i) a high Seebeck coefficient ( S T ) to generate a detectable thermoinduced voltage, (ii) a low thermal conductivity to maintain a stable temperature gradient (Δ T ) across the material and constant output voltage, (iii) a high electrical conductivity to facilitate efficient current transmission, and (iv) well-designed structural features to trigger a change in electrical resistance in response to external pressure .…”

A novel flexible sensor for double-parameter decoupling measurement of temperature and pressure with high sensitivity and wide range

“…[33][34][35][36] However, presently, the main issue with these sensors is that their measurement range and sensitivity are compromised due to the greater focus on the decoupled sensing of temperature and pressure. 37 Accordingly, Ma introduced a double-parameter tactile sensor based on piezoelectric materials, which could simultaneously measure force and temperature and exhibited advantages such as high sensitivity and fast response. However, it lacked a temperature compensation method and exhibited reliability problems such as signal interference.…”