Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution Measurement
Foot pressure measurement plays an essential role in healthcare applications, clinical rehabilitation, sports training and pedestrian navigation. Among various foot pressure measurement techniques, in-shoe sensors are flexible and can measure the pressure distribution accurately. In this paper, we d...
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| Format: | Article |
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MDPI AG
2021-09-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/21/18/6082 |
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| author | Dhivakar Rajendran Rajarajan Ramalingame Saravanan Palaniyappan Guntram Wagner Olfa Kanoun |
| author_facet | Dhivakar Rajendran Rajarajan Ramalingame Saravanan Palaniyappan Guntram Wagner Olfa Kanoun |
| author_sort | Dhivakar Rajendran |
| collection | DOAJ |
| description | Foot pressure measurement plays an essential role in healthcare applications, clinical rehabilitation, sports training and pedestrian navigation. Among various foot pressure measurement techniques, in-shoe sensors are flexible and can measure the pressure distribution accurately. In this paper, we describe the design and characterization of flexible and low-cost multi-walled carbon nanotubes (MWCNT)/Polydimethylsiloxane (PDMS) based pressure sensors for foot pressure monitoring. The sensors have excellent electrical and mechanical properties an show a stable response at constant pressure loadings for over 5000 cycles. They have a high sensitivity of 4.4 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">Ω</mi></semantics></math></inline-formula>/kPa and the hysteresis effect corresponds to an energy loss of less than 1.7%. The measurement deviation is of maximally 0.13% relative to the maximal relative resistance. The sensors have a measurement range of up to 330 kPa. The experimental investigations show that the sensors have repeatable responses at different pressure loading rates (5 N/s to 50 N/s). In this paper, we focus on the demonstration of the functionality of an in-sole based on MWCNT/PDMS nanocomposite pressure sensors, weighing approx. 9.46 g, by investigating the foot pressure distribution while walking and standing. The foot pressure distribution was investigated by measuring the resistance changes of the pressure sensors for a person while walking and standing. The results show that pressure distribution is higher in the forefoot and the heel while standing in a normal position. The foot pressure distribution is transferred from the heel to the entire foot and further transferred to the forefoot during the first instance of the gait cycle. |
| first_indexed | 2024-03-10T07:14:15Z |
| format | Article |
| id | doaj.art-3b481988d2a0469abccecfca8b41ffa3 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T07:14:15Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-3b481988d2a0469abccecfca8b41ffa32023-11-22T15:11:17ZengMDPI AGSensors1424-82202021-09-012118608210.3390/s21186082Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution MeasurementDhivakar Rajendran0Rajarajan Ramalingame1Saravanan Palaniyappan2Guntram Wagner3Olfa Kanoun4Measurement and Sensor Technology, Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, GermanyMeasurement and Sensor Technology, Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, GermanyComposites and Material Compounds, Institute of Material Science and Engineering (IWW), Technische Universität Chemnitz, Erfenschlager Straße 73, 09125 Chemnitz, GermanyComposites and Material Compounds, Institute of Material Science and Engineering (IWW), Technische Universität Chemnitz, Erfenschlager Straße 73, 09125 Chemnitz, GermanyMeasurement and Sensor Technology, Technische Universität Chemnitz, Reichenhainer Straße 70, 09126 Chemnitz, GermanyFoot pressure measurement plays an essential role in healthcare applications, clinical rehabilitation, sports training and pedestrian navigation. Among various foot pressure measurement techniques, in-shoe sensors are flexible and can measure the pressure distribution accurately. In this paper, we describe the design and characterization of flexible and low-cost multi-walled carbon nanotubes (MWCNT)/Polydimethylsiloxane (PDMS) based pressure sensors for foot pressure monitoring. The sensors have excellent electrical and mechanical properties an show a stable response at constant pressure loadings for over 5000 cycles. They have a high sensitivity of 4.4 k<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">Ω</mi></semantics></math></inline-formula>/kPa and the hysteresis effect corresponds to an energy loss of less than 1.7%. The measurement deviation is of maximally 0.13% relative to the maximal relative resistance. The sensors have a measurement range of up to 330 kPa. The experimental investigations show that the sensors have repeatable responses at different pressure loading rates (5 N/s to 50 N/s). In this paper, we focus on the demonstration of the functionality of an in-sole based on MWCNT/PDMS nanocomposite pressure sensors, weighing approx. 9.46 g, by investigating the foot pressure distribution while walking and standing. The foot pressure distribution was investigated by measuring the resistance changes of the pressure sensors for a person while walking and standing. The results show that pressure distribution is higher in the forefoot and the heel while standing in a normal position. The foot pressure distribution is transferred from the heel to the entire foot and further transferred to the forefoot during the first instance of the gait cycle.https://www.mdpi.com/1424-8220/21/18/6082foot pressure distributiongait analysisflexible sensorswearable sensorsmulti carbon nanotubes (MWCNT)polydimethylsiloxane (PDMS) |
| spellingShingle | Dhivakar Rajendran Rajarajan Ramalingame Saravanan Palaniyappan Guntram Wagner Olfa Kanoun Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution Measurement Sensors foot pressure distribution gait analysis flexible sensors wearable sensors multi carbon nanotubes (MWCNT) polydimethylsiloxane (PDMS) |
| title | Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution Measurement |
| title_full | Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution Measurement |
| title_fullStr | Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution Measurement |
| title_full_unstemmed | Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution Measurement |
| title_short | Flexible Ultra-Thin Nanocomposite Based Piezoresistive Pressure Sensors for Foot Pressure Distribution Measurement |
| title_sort | flexible ultra thin nanocomposite based piezoresistive pressure sensors for foot pressure distribution measurement |
| topic | foot pressure distribution gait analysis flexible sensors wearable sensors multi carbon nanotubes (MWCNT) polydimethylsiloxane (PDMS) |
| url | https://www.mdpi.com/1424-8220/21/18/6082 |
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