Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand Orthoses
Additively manufactured wrist–hand orthoses (3DP-WHOs) offer several advantages over traditional splints and casts, but their development based on a patient’s 3D scans currently requires advanced engineering skills, while also recording long manufacturing times as they are commonly built in a vertic...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/15/12/2737 |
| _version_ | 1797592934776832000 |
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| author | Diana Popescu Florin Baciu Daniel Vlăsceanu Rodica Marinescu Dan Lăptoiu |
| author_facet | Diana Popescu Florin Baciu Daniel Vlăsceanu Rodica Marinescu Dan Lăptoiu |
| author_sort | Diana Popescu |
| collection | DOAJ |
| description | Additively manufactured wrist–hand orthoses (3DP-WHOs) offer several advantages over traditional splints and casts, but their development based on a patient’s 3D scans currently requires advanced engineering skills, while also recording long manufacturing times as they are commonly built in a vertical position. A proposed alternative involves 3D printing the orthoses as a flat model base and then thermoforming them to fit the patient’s forearm. This manufacturing approach is faster, cost-effective and allows easier integration of flexible sensors as an example. However, it is unknown whether these flat-shaped 3DP-WHOs offer similar mechanical resistance as the 3D-printed hand-shaped orthoses, with a lack of research in this area being revealed by the literature review. To evaluate the mechanical properties of 3DP-WHOs produced using the two approaches, three-point bending tests and flexural fatigue tests were conducted. The results showed that both types of orthoses had similar stiffness up to 50 N, but the vertically built orthoses failed at a maximum load of 120 N, while the thermoformed orthoses could withstand up to 300 N with no damages observed. The integrity of the thermoformed orthoses was maintained after 2000 cycles at 0.5 Hz and ±2.5 mm displacement. It was observed that the minimum force occurring during fatigue tests was approximately −95 N. After 1100–1200 cycles, it reached −110 N and remained constant. The outcomes of this study are expected to enhance the trust that hand therapists, orthopedists, and patients have in using thermoformable 3DP-WHOs. |
| first_indexed | 2024-03-11T02:01:18Z |
| format | Article |
| id | doaj.art-b9d932aea6f34b8fbd3ee452444a1a6c |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-11T02:01:18Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-b9d932aea6f34b8fbd3ee452444a1a6c2023-11-18T12:14:05ZengMDPI AGPolymers2073-43602023-06-011512273710.3390/polym15122737Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand OrthosesDiana Popescu0Florin Baciu1Daniel Vlăsceanu2Rodica Marinescu3Dan Lăptoiu4Department of Robotics and Production Systems, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, RomaniaDepartment of Strength of Materials, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, RomaniaDepartment of Strength of Materials, Faculty of Industrial Engineering and Robotics, University Politehnica of Bucharest, 060042 Bucharest, RomaniaDepartment of Orthopedics, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, RomaniaDepartment of Orthopedics, Colentina Clinical Hospital, 020125 Bucharest, RomaniaAdditively manufactured wrist–hand orthoses (3DP-WHOs) offer several advantages over traditional splints and casts, but their development based on a patient’s 3D scans currently requires advanced engineering skills, while also recording long manufacturing times as they are commonly built in a vertical position. A proposed alternative involves 3D printing the orthoses as a flat model base and then thermoforming them to fit the patient’s forearm. This manufacturing approach is faster, cost-effective and allows easier integration of flexible sensors as an example. However, it is unknown whether these flat-shaped 3DP-WHOs offer similar mechanical resistance as the 3D-printed hand-shaped orthoses, with a lack of research in this area being revealed by the literature review. To evaluate the mechanical properties of 3DP-WHOs produced using the two approaches, three-point bending tests and flexural fatigue tests were conducted. The results showed that both types of orthoses had similar stiffness up to 50 N, but the vertically built orthoses failed at a maximum load of 120 N, while the thermoformed orthoses could withstand up to 300 N with no damages observed. The integrity of the thermoformed orthoses was maintained after 2000 cycles at 0.5 Hz and ±2.5 mm displacement. It was observed that the minimum force occurring during fatigue tests was approximately −95 N. After 1100–1200 cycles, it reached −110 N and remained constant. The outcomes of this study are expected to enhance the trust that hand therapists, orthopedists, and patients have in using thermoformable 3DP-WHOs.https://www.mdpi.com/2073-4360/15/12/27373D printingthermoformingwrist–hand orthosismechanical behaviorcustomizationflexural fatigue |
| spellingShingle | Diana Popescu Florin Baciu Daniel Vlăsceanu Rodica Marinescu Dan Lăptoiu Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand Orthoses Polymers 3D printing thermoforming wrist–hand orthosis mechanical behavior customization flexural fatigue |
| title | Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand Orthoses |
| title_full | Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand Orthoses |
| title_fullStr | Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand Orthoses |
| title_full_unstemmed | Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand Orthoses |
| title_short | Investigations on the Fatigue Behavior of 3D-Printed and Thermoformed Polylactic Acid Wrist–Hand Orthoses |
| title_sort | investigations on the fatigue behavior of 3d printed and thermoformed polylactic acid wrist hand orthoses |
| topic | 3D printing thermoforming wrist–hand orthosis mechanical behavior customization flexural fatigue |
| url | https://www.mdpi.com/2073-4360/15/12/2737 |
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