Interface structure design of 3D printing flexible stretchable discrete functional gradient substrate

doi:10.19491/j.issn.1001-9278.2025.09.011

Abstract

Abstract:

To address the challenges of interfacial separation and poor tensile properties in discrete functional gradient substrates， this study proposed a novel substrate structure based on interface design. Using PDMS⁃based materials as an example， functional gradient flexible substrates were fabricated via extrusion⁃based 3D printing. Six distinct interface structures were evaluated for their tensile properties， with the island structure demonstrating the most effective suppression of interfacial delamination. Orthogonal experiments were conducted to optimize the island structure parameters， using tensile ratio as the key performance metric. The optimal configuration was determined as follows： 4 islands per unit length， an island⁃to⁃bridge length ratio of 1， a width ratio of 1.75， and an edge margin ratio of 0.07. The results indicated that the island structure significantly enhanced interfacial cohesion， improving the tensile ratio by 1.82 times compared to conventional designs.

Key words: discrete functional gradient flexible substrate, tensile property, interface structure design

CLC Number:

TQ320.66

HAN Yusheng, YANG Jianjun, ZHENG Ying, WANG Yaxiao. Interface structure design of 3D printing flexible stretchable discrete functional gradient substrate[J]. China Plastics, 2025, 39(9): 68-74.

Figures/Tables 15

Fig.1. Extruded two⁃nozzle 3D printer

Fig.2. Discrete function gradient substrate printing process flow

Fig.3. Substrate basic structure

Fig.4. Multiple interface structures

Fig.5. Tensile stress diagram of six interface shapes

Fig.6. VCCT crack growth strain

Fig.7. Tensile test of six interface shapes

Fig.8. Stress⁃strain curves at six interfaces

Fig.9. Interface structure parameter

Fig.10. Single factor horizontal experiment results

水平	n	a/b	e/f	c/W
1	2	0.5	1.25	0.05
2	3	1	1.75	0.07
3	4	1.5	2.5	0.09
4	5	2	3	0.11

Tab.1. The value of each factor level

实验序号	n	a/b	e/f	c/W	拉伸率/%
1	2	1.5	1.25	0.07	76.33
2	2	2.0	2.50	0.09	71.38
3	2	0.5	3.00	0.05	67.88
4	2	1.0	1.75	0.11	80.61
5	3	1.5	3.00	0.11	90.17
6	3	1.0	2.50	0.07	105.42
7	3	0.5	1.25	0.09	90.41
8	3	2.0	1.75	0.05	89.80
9	4	0.5	2.50	0.11	112.28
10	4	1.5	1.75	0.09	122.69
11	4	2.0	3.00	0.07	110.82
12	4	1.0	1.25	0.05	98.68
13	5	0.5	1.75	0.07	129.30
14	5	1.0	3.00	0.09	106.70
15	5	1.5	2.50	0.05	101.67
16	5	2.0	1.25	0.11	93.53

Tab.2. Orthogonal experimental design of 4⁃factor 4⁃levle

指标	因素
指标	n	a/b	e/f	c/W
$K 1$	296.23	399.89	358.98	358.06
$K 2$	375.82	391.44	422.43	421.90
$K 3$	444.50	390.89	390.78	391.21
$K 4$	431.22	365.56	375.59	376.61
$K 1 ¯$	74.06	99.97	89.74	89.51
$K 2 ¯$	93.95	97.86	105.61	105.47
$K 3 ¯$	111.13	97.72	97.69	97.80
$K 4 ¯$	107.81	91.39	93.90	94.15
R	37.07	8.58	15.86	15.96

指标	因素
指标	n	a/b	e/f	c/W
$K 1$	296.23	399.89	358.98	358.06
$K 2$	375.82	391.44	422.43	421.90
$K 3$	444.50	390.89	390.78	391.21
$K 4$	431.22	365.56	375.59	376.61
$K 1 ¯$	74.06	99.97	89.74	89.51
$K 2 ¯$	93.95	97.86	105.61	105.47
$K 3 ¯$	111.13	97.72	97.69	97.80
$K 4 ¯$	107.81	91.39	93.90	94.15
R	37.07	8.58	15.86	15.96

Tab.3. Range analysis of test results

Fig.11. The influence of various factors on the tensile ratio

Fig.12. Maximum tensile ratio of linear and island⁃shaped interfacial gradient substrates

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