Page 308 - IJB-9-1

International Journal of Bioprinting Error assessment and correction

Figure 1. (A) A schematic diagram demonstrating the power source of extrusion-based bioprinting. From left to right, the schematic shows screw-driven
dispensing, pneumatic dispensing, and piston-driven dispensing. (B) Examples for identifying and correcting errors based on computer vision. The Sobel
operator is used to obtain the original printing error, and a complete correction plan is prepared using the normal vector approach.

At present, the research field of bioprinting includes heart pointed out that high resolution is an important
scaffold fabrication [7,8] , organ-on-a-chip manufacturing , requirement for stable manufacturing of the heart .
[9]
[23]
tissue repair , and toxicity testing [11,12] . Building patient- Hence, it is necessary to emphasize and improve on the
[10]
specific organs to alleviate organ shortages remains a major resolution of extrusion-based bioprinting.
challenge in the bioprinting field [13-15] . The defect in the deviation of the actual printing
Bioprinting methods can be divided into inkjet-based, path from the predetermined path, and the deviation
laser-based, extrusion-based, and stereolithography-based error value that remains in the final printed organ are
bioprinting . Compared with other printing methods, the main reasons for the low resolution of extrusion-
[15]
extrusion-based bioprinting is the most often used, as it has based bioprinting [24,25] . Normally, the deviation value
high throughput and a fast printing speed [16-18] . Extrusion- between the reference path and the printing path is small
based bioprinting mainly relies on rotation dispensing, in linear shape areas; however, the deviation error shows
air pressure dispensing, or force dispensing, as shown in a significant increasing tendency when the path changes
Figure 1A. to a curved shape. The whole helix is composed of the
Although extrusion-based bioprinting has more antihelix and helix, which is a curved structure that has
advantages compared to other printing methods, the been printed in many studies. However, the research
low printing resolution is the main reason that limits the on helix printing still lacks a method that can precisely
advancement of extrusion-based bioprinting in various control the printing path and reduce the deviation error
fields [19-22] . Moreover, many studies have pointed out that value between the printing path and the reference path;
resolution is an important parameter for bioprinting; moreover, there is still much room for improvement in
for instance, a study on artificially printing human terms of printing resolution [26,27] .

Volume 9 Issue 1 (2023)olume 9 Issue 1 (2023)
V 300 https://doi.org/10.18063/ijb.v9i1.644