A new two-step adaptive direct slicing approach for bio-scaffolds in tissue engineering

Abstract

Purpose This paper aims to propose the new two-step adaptive direct slicing method for building bio-scaffold with digital micro-mirror device (DMD)-based MPμSLA systems. Design/methodology/approach In this paper, the authors proposed a new approach to directly slice a scaffold’s CAD model (i.e the three-dimensional model built by computer-aided design platforms) and save the slices’ data as BMP (bitmap, i.e. the data format used in DMD) files instead of other types of two-dimensional patterns as an intermediary. The proposed two-step strategy in this paper, i.e. a CAD model’s exterior surface and internal architecture were sliced, respectively, at first, and then assembled together to obtain one intact slice. The assembly process is much easier and convenient based on the slice data in BMP format. To achieve the adaptive slicing for both the exterior part and internal part, two new indices, the exterior surface-dominated index and internal architecture-dominated index, are, respectively, utilized as the error estimation indices. The proposed approach in this paper is developed on SolidWorks platform, but it can also be implemented on other platforms. Findings The authors found that the approach is not only more accurate but also more efficient by avoiding the repeated running of those inefficient rasterization programs. The approach is able to save computer resource and time, and enhance the robustness of slicing program, as well as is appropriate for the scaffolds’ model with internal pore architecture and external free-form surface. Practical implications Bio-scaffolds in tissue engineering require precise control over material distribution, such as the porosity, connectivity, internal pore architecture and external free-form surface. The proposed two-step adaptive direct slicing approach is a good balance of slicing efficiency and accuracy and can be useful for slicing bio-scaffolds’ models. Originality/value This paper gives supports to build bio-scaffold with DMD-based MPμSLA systems.

Coupling control of pore size and spatial distribution in bone scaffolds based on a random strategy for additive manufacturing

“…For instance, cell growth, migration and nutrient flow heavily rely on the pore interconnectivity, and there should be a balance between small and large pores to achieve appropriate mechanical strength, specific surface area, cell migration, diffusion of nutrients, removal of waste, etc. (Derby, 2012; Karageorgiou and Kaplan, 2005; Khoda et al , 2013; Liu and Li, 2017; Murphy et al , 2010; Zhang et al , 2014). In addition, to form multiple tissues and tissue interfaces, such as for articular cartilage/bone transplant, gradients in pore sizes are preferred (Li et al , 2014).…”