3D multi-nozzle system with dual drives highly potential for 3D complex scaffolds with multi-biomaterials

Recently, additive manufacturing is one of the most focused research topics due to its explosive development, especially in manufacturing engineering and medical science. In order to build 3D complex scaffolds with multi-biomaterials for clinical application, a new 3D multi-nozzle system with dual-mode drives, i.e. ejection and extrusion was developed. In this paper, much effort was made to gain fine control of droplet and excellent coordination during fabrication. Specifically, the parameters that influence the size and stability of droplet most was intensively studied. Considering that the biomaterials used in the future may have much difference in properties, the combination of parameters was investigated to facilitate the settings for certainsized droplets, which are potentially eligible for bio-printing. The dispensing nozzles can work well both in independent and convergent mode, which can be freely switched. Outstanding to the most currently used 3D bio-printing techniques, this system can fabricate scaffolds with multi-materials of both low viscosity (by pneumatic dispensing) and high viscosity (through motor extrusion). It is highly expected that this system can satisfy clinical application in the near future

Number of unidirectional edges <i>u_m</i>, bidirectional <i>b_m</i>, and nonedges <i>n_m</i> and the symmetry factors <i>s_m</i> of all three-vertices subgraphs.

<p>Note: the mistakes of the value of <i>s_m</i> in the expression for symmetry factors and also the values in reference <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099634#pone.0099634-Fretter1" target="_blank">[53]</a> had been modified here.</p

Detection boundaries for subgraphs in the industrial ecosystem at Kalundborg (α = 0.1).

<p>Detection boundaries for subgraphs in the industrial ecosystem at Kalundborg (α = 0.1).</p

All connected directed subgraphs of size three.

<p>All connected directed subgraphs of size three.</p

Analytical solutions to the suitable detection range of all subgraphs templates.

<p>Note: y represents the number of edges in the network, and x represents the number of vertices.</p

The structure and degree distribution of the industrial network at Kalundborg.

<p>(<b>A</b>) Red vertices represent enterprises and links represent material and energy flow. The chronological order of these directed edges are marked with the serial number 1, 2…, 35. (<b>B</b>) The in-degree and out-degree distribution in 2011.</p

The amount and the percentage of each subgraph template in a randomized network with <i>N</i> = 100.

<p>(<b>A</b>) The change of the count of each subgraph template, with the connection density . (<b>B</b>) The change of the percentage of each subgraph template with .</p

Results of motifs identification in a random experiment.

<p>(<b>A</b>) The variation of the significance metric Z-score in the whole evolutionary process. (<b>B</b>) Identification results of motifs when <i>n</i> is equal to 1, 2……10, separately. The accuracy of each <i>n</i> is compared with the ideal result in the first row.</p

Variation of in the evolutionary process of the industrial network at Kalundborg.

<p>(<b>A</b>) The relationship between the switching times <i>n</i> and at <i>E</i> = 14, 16, 18, 20, 22, 24. (<b>B</b>) The relationship between the rewiring ratio <i>r</i> (<i>n</i>/<i>E</i>) and at <i>E</i> = 14, 16, 18, 20, 22, 24, 30, 35. The exponential function is used to approximate the curve of randomized process of the network at each time point. And the curves at <i>E</i> = 14, 16 are marked in gray.</p

Identifying motifs in the evolutionary process of the industrial ecosystem at Kalundborg from 1961–2011.

<p>(<b>A</b>) The variation of the percentage of four subgraphs (No.1–4) and that of all three-vertices subgraphs. (<b>B</b>) The result of subgraph No.1. The suitable detection range is the right area in gray. Its frequency is compared with that of the average level in the ensemble of 1000 randomized networks. The error bar, marked by red sticks, represents the standard deviation. The variation of statistical metric Z-score is marked by hollow black box. (<b>C</b>) The result of subgraph No.2 and the corresponding significant region. (<b>D</b>) The situation of subgraph No.4.</p