Preparation of flexible sensors for requirement of thoracic and abdominal respiration detection

doi:10.19491/j.issn.1001-9278.2025.06.008

Abstract

Abstract:

This study employs the operating principle of semiconductor⁃based resistive strain sensors to fabricate an intermediate conductive layer using two distinct methods： spatially⁃confined forced assembly and screen printing. Comparative analysis revealed that the sensor produced via spatially⁃confined forced assembly demonstrated superior suitability for pre⁃radiotherapy breathing training in patients. Under a maximum applied strain of 24 %， the sensor exhibited stable performance， with a fitted sensitivity of K=0.0015 V/mm and a repeatability of 96.67 %. Tensile testing at 10 % strain yielded a rapid response time （T_r≈137 ms）， meeting the requirements for real⁃time monitoring. Forward and reverse stroke output⁃input curve measurements further revealed a low return error （δ_H=1.06 %）， demonstrating the working stability of the sensor during prolonged operation. Finally， respiratory signals were successfully collected from ten individuals with varying chest circumferences， highlighting the clinical utility of the sensor in medical diagnostics and patient⁃specific respiratory monitoring.

Key words: flexible sensor, sandwich structure, space?limited domain forced assembly, respiratory monitoring, stretchability

CLC Number:

TQ325.1⁺2

CHEN Yuanmin, ZHAO Mengyu, QIU Siyuan, LI Yajiao, WANG Wenhao, WANG Hao, ZHU Guangying, SUN Jingyao. Preparation of flexible sensors for requirement of thoracic and abdominal respiration detection[J]. China Plastics, 2025, 39(6): 36-41.

Figures/Tables 12

原料名称	含量/份
DCP	1.0
KH⁃570	0.357
白炭黑	7.53
110⁃0硅胶	100

Tab.1. Composition of outer insulating materials

原料名称	含量/份
DCP	1
导电炭黑	10
110⁃2硅胶	100

Tab.2. Composition of conductive materials in the middle layer

Fig.1. Schematic diagram of the preparation of the insulation layer

Fig.2. Pattern of the middle conductive layer

Fig.3. Schematic diagram of the preparation of conductive layer by screen printing

Fig.4. Actual wearing effect of the chest and abdomen respiratory flexible sensor

Fig.5. Voltage curves with different stretch amounts

Fig.6. Sensor response time

Fig.7. The difference between the forward and reverse strokes

编号	电压/V
1	3.981
2	3.992
3	3.983
4	3.989
5	3.986
6	3.991
7	3.976
8	3.982
9	3.988
10	3.984
11	3.986
12	3.987
13	3.990
14	3.979
15	3.987
16	3.989
17	3.983
18	3.986
19	3.990
20	3.987

Tab.3. Voltage value table for full⁃scale input

Fig.8. Amplitude plot of chest inhalation and exhalation

Fig.9. Ten samples of chest breathing test data

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