Table 1.

Stiffness (elastic modulus) for selected PI concentrations and UV exposure times in each layer

0.05% PI & 0.1 s UV exposure in each layer			0.07% PI & 0.1 s UV exposure in each layer
GelMA (%)	PEGDA (%)	Modulus (kPa)	GelMA (%)	PEGDA (%)	Modulus (kPa)
0		26.0 ± 0.6	0		N/A
3	20	24.0 ± 5.0	3	20	75.0 ± 7.0
5		N/A	5		56.0 ± 6.0
0		47.0 ± 3.0	0		97.0 ± 10
3	30	49.0 ± 6.0	3	30	106 ± 20
5		N/A	5		109 ± 10
0		420 ± 6.0	0		920 ± 60
3	40	660 ± 30	3	40	530 ± 70
5		N/A	5		650 ± 40

0.05% PI & 0.2 s UV exposure in each layer			0.07% PI & 0.2 s UV exposure in each layer
GelMA (%)	PEGDA (%)	Modulus (kPa)	GelMA (%)	PEGDA (%)	Modulus (kPa)
0		78.0 ± 3.0	0		51.0 ± 1.0
3	20	41.0 ± 2.0	3	20	120 ± 7.0
5		52.0 ± 5.0	5		100 ± 9.0
0		97.0 ± 20	0		110 ± 30
3	30	140 ± 60	3	30	180 ± 30
5		100 ± 1.0	5		130 ± 10
0		880 ± 30	0		110 ± 30
3	40	1180 ± 90	3	40	880 ± 60
5		750 ± 10	5		980 ± 50