Silver Telluride Nanowire Assembly for High‐Performance Flexible Thermoelectric Film and Its Application in Self‐Powered Temperature Sensor

Abstract

Flexible thermoelectric materials that enable harvesting electricity from human body heat or an ambient temperature gradient have potential applications in self‐powered flexible wearable electronics. The development of more efficient and flexible n‐type thermoelectric materials, however, is highly desired but challenging. Herein, reported is a nylon substrate supported fabric silver telluride (Ag2Te) nanowire network used as flexible n‐type thermoelectric materials, by the combination of vacuum filtrated assembly and mechanical pressing method. The prepared silver telluride nanowire films show optimal thermoelectric properties with the Seebeck coefficient of −129.5 µV K−1 and electrical conductivity of 187.78 S cm−1, leading to the highest power factor of 315.1 µW m−1 K2. Owing to the elimination of Peierls stress in the fabrics interlocking structure, the silver telluride nanowire films exhibit good flexibility, as the thermoelectric properties only have a change below 10% after 500 bending cycles. Based on the silver telluride nanowire film, a flexible self‐powered temperature sensor is fabricated for detecting the temperature from a human finger. The sensor shows high sensitivity that its response time and reset time are about 1.05 and 2.1 s, respectively. The results imply that silver telluride nanowire films have great potential applications in flexible thermoelectric energy conversion and self‐powered temperature sensing.

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

“…This sensitivity is among the highest values reported for a thermoelectric flexible temperature sensor. [7,37,38,42,43] Moreover, the sensitivity retains 108.9 µV K −1 after being placed in ambient environment for three months showing negligible degradation, demonstrating good stability of thermoelectric conversion function of the device in the ambient atmosphere. Notably, the inset in Figure 2b shows that small temperature gradients of 0.3 and 0.4 K in the ambient environment can be unambiguously detected, respectively, with clear steps in the V versus T curve, implying that temperature sensing resolution could be as high as 0.1 K at RT.…”

“…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.…”

Textile‐Based Thermoelectric Generators and Their Applications

“…Furthermore, the TE thermal sensor also possessed good stretchability with stable TE performance and showed potential application for detecting strain . Zeng et al also investigated the thermal sensing performance of n‐type Ag 2 Te nanowire TE films supported by nylon fabrics. Due to the interlocking structure, the fabricated Ag 2 Te nanowire films displayed good flexibility and high power factor of 315 μW m −1 K −2 .…”

Identifying human body states by using a flexible integrated sensor

“…Recent progress in flexible and wearable electronics has enhanced the possibility of continuous healthcare monitoring in daily life through the development of many kinds of wearable, conformable sensors [1][2][3][4][5][6][7][8][9][10] . These sensors mainly include flexible temperature sensors [11][12][13][14][15][16] , pressure/force sensors [17][18][19][20][21][22][23][24][25] , humidity sensors [26][27][28][29] , ultrasonic sensors 30,31 , optical sensors [32][33][34] , and biochemical sensors, but most are created to achieve noninvasive detection for a single vital indicator, such as body temperature (BT), heart rate (HR)/arterial pulse, blood pressure (BP), respiratory waves (RWs), or jugular venous pulse. To identify or diagnose human body states, multiple different vital indicators should be monitored continuously.…”