Page 107 - IJB-9-2

International Journal of Bioprinting Holistic charge-based MEW scaffold model

A B C

Figure 6. Effect of lateral location on jet deposition. (A) Lateral characteristic curves at different z. Parts of the orange curve in (A) denoted by ①②③ are
locally enlarged and superimposed at the peak values in (B) for comparative analysis of the slopes. The decreasing rate of the energy function at the outer
side is lowest for ① and highest for ③. The dash-dotted line denotes the prescribed path. (C) shows the dependence of the “spindle” size on lateral location
(layer printing time 57 s). The closer it is to the scaffold periphery, the more obvious the “spindle-like” structure is. Voltage: 16 kV; pressure: 70 kPa; material
temperature: 95°C; stage speed: 16 mm/s; layer printing time 57 s. α = β = 3, ξ = 60, η = 1, K = 3. All the curves are translated to compare their difference.

A B

C E
D

Figure 7. Effect of grid number on jet deposition. (A) and (B) show the dependence of lateral characteristic curves on K at z=60 and 10, respectively. (C–E)
show the variation of “spindle-like” structure when K increases from 2 to 5. Due to the scope of the camera, (E) shows only part of the scaffold. As the grid
number increases, the “spindle-like” structure becomes less significant. Voltage: 16 kV; pressure: 70 kPa; material temperature: 95°C; translational stage
speed: 15 mm/s; layer printing time 92 s. α = β = 3, ξ = 60, η = 1. All the curves are translated when necessary to compare their difference.

residual charge within the layers of the scaffold is still in the local effect weakens based on the proposed model.
the negative regime, it is assumed that β < 1 . Below a critical value, the local effect is so weak that it is
[30]
With these modifications, the energy surface and the unable to correct for the lateral deviation resulting in the
lateral characteristic curves at z = 5 and z = 2 are shown in occurrence of “fiber bridging” phenomenon.
Figure 8B and 8C, respectively. As explained before, when Now, it is possible to explain the effect of N as well as
β < 1, the local effect and polarization effect is synergistic d on the “fiber bridging” phenomenon. As stated before,
f
and thus indifferentiable. Therefore, further decrements in when β < 1, increasing N is equivalent to decreasing
z will not provide more information for Figure 8. It is evident β (seen in the last point in section 3.2.4). Therefore, the
that the global effect will initiate the lateral deviation of jet global effect becomes increasingly strong (Figure 8D),
deposition. As the interfiber distance decreases, however, while the local effect is not affected significantly, which

Volume 9 Issue 2 (2022) 99 https://doi.org/10.18063/ijb.v9i2.656