WO2015038072A1

WO2015038072A1 - A 3d printer with a plurality of interchangeable printing modules and methods of using said printer

Info

Publication number: WO2015038072A1
Application number: PCT/SG2014/000431
Authority: WO
Inventors: Mingwei FAN; Lye Huat Conrad SNG
Original assignee: Bio3D Technologies Pte Ltd
Priority date: 2013-09-12
Filing date: 2014-09-12
Publication date: 2015-03-19

Abstract

There is provided a 3D printer with a plurality of interchangeable extruder modules. Each of the plurality of extruder modules is of a type such as, for example, syringe-based extruder module, filament-based extruder module, jet extruder module and the like. Methods of using the 3D printer are also provided.

Description

A 3D PRINTER WITH A PLURALITY OF INTERCHANGEABLE PRINTING MODULES AND

METHODS OF USING SAID PRINTER

FIELD OF INVENTION

The invention relates to the field of 3D printers and 3D printing. BACKGROUND The increasing affordability of 3D printers is now making 3D printing more accessible to anyone. Most consumer and/or desktop 3D printers currently in the market utilise techniques such as, for example, Fused Filament Fabrication (FFF), Fused Deposition Modelling (FDM), Digital Light Projection (DLP), stereolithography, and the like. Given the infancy of 3D printing, the 3D printing landscape continues to evolve. Many home users are already using 3D printers to print items such as toys, figurines, replacement parts, wearable fashion objects and so forth. Industrial use of such 3D printers is still mainly in product rapid prototyping and manufacturing of medical devices such as, for example, hearing aids, orthopaedic implants and so forth.

A 3D printer typically creates a 3D object by an additive process. A 3D model is firstly designed using Computer Aided Design (CAD) software, and then sliced into many layers by a slicing software or engine. The object will be built by moving the extruder arid printer's nozzle (both makes up the print head) in a coordinated motion in all three Cartesian axes (X, Y and Z), laying down successive layers of the print material on a surface until the object is fully built from bottom up. The actions and 3-dimensional movements of the extruder and nozzle where the print material is extruded are determined and controlled by a numerical control programming language, typically G-code in consumer 3D printers. A consumer/desktop 3D printer lowers the cost and learning curve of fabrication compared to traditional fabrication techniques, and brings about new applications, especially in biotechnology and biomedicine. Traditionally, 3D printers print plastics such as Acrylonitrile butadiene styrene (ABS), Polylactic acid (PLA) and Polyvinyl alcohol (PVA). In recent years, materials engineering has enabled new materials such as ceramic, glass, sand, and metals to be printed using 3D printers. Ongoing research for new materials used in 3D printing of inanimate material objects has led to growing interest in bio-printing. Bio-printing generally refers to 3D printing with cells, biomaterials and other biologies. Instead of printing layers of layers of plastics or even titanium in the typical 3D printing, a bio-printer prints thin layers of organic material such as living cells.

By 3D printing living cells and other organic materials, scientists and researchers eventually hope that a functional tissue or organ can be fabricated using 3D printing. Thus bio-printing can potentially lead to replacement human organs (such as skin or kidney) which can be printed directly from a 3D printer using an individual's own cells. This will substantially minimise the incidence of transplanted replacement organs being rejected by the individual's body.

Current 3D printers and plotters typically have a fixed number/type of extruders and print heads. This means that an extruder in a 3D printer is usually configured for printing a specific type of material only. If a user wishes to print using other materials that are not supported, the user will have no alternative but to purchase a new machine which supports printing of the desired material. It may be possible for the user to remove the existing extruder and install a new one. However this involves certain level of experience/technical knowledge which most users do not possess. Moreover not all 3D printers can be easily modified/tampered with. Some high-end professional grade 3D printers can support printing of different materials, but such printers cost substantially more, require a steeper learning curve, incur higher maintenance costs and take up additional space. Furthermore, even though some high-end professional grade 3D printers support up to maximum of four extruders, this effectively restricts the maximum number of printing materials to four. Moreover, even though professional grade 3D printers are able to support a maximum of four extruders, it is usually possible to only print a single object at a time.

In this regard, it is desirable if a higher number of extruders are made available for use in a single 3D printer as it leads to a greater variety in printed products and faster fabrication as each individual extruder can be programmed to do different tasks.

SUMMARY

In a first aspect, there is provided a 3D printer including a back plate; and a plurality of printing modules, the plurality of printing modules being mounted to the back plate. It is advantageous that each of the plurality of printing modules is mounted to the back plate using a mounting means such as, for example, fitment within a slot, magnetic attraction, hook-and-loop attachment, interlocking of parts using a rigid structure and so forth. The back plate is either affixed to the 3D printer or integrated with the 3D printer. The plurality of printing modules can be configured to be rotatable. Each of the plurality of printing modules is of a type such as, for example, a syringe-based extruder module, filament-based extruder module, UV curing module, inkjet printing module, jet extruder module and the like. A syringe of the syringe-based extruder module can be secured using a shaped piece of plastic fitted in a receptor, the shaped piece of plastic being further secured within the receptor using a rigid strip of material. Alternatively, the syringe of the syringe-based extruder module may be secured using a knob which, when tightened, pushes a block against the syringe to secure the syringe. Extrusion-based modules can cover contact- based and non-contact extrusion methods. The printing modules can also utilize other printing techniques such as, for example, laser-based, UV-based (photocuring), inkjet-based printing and so forth. Each of the plurality of printing modules can be configured to be integrated with a laser or other features.

There is also provided a jet extruder module that includes an extended tube; a nozzle at a first end of the extended tube; an electronic solenoid valve at a second end of the extended tube; and a tube connected to the electronic solenoid valve, the tube being connected to a high pressured liquid source. Preferably, liquid is aerosolized at the first end of the extended tube. It is also preferable that the electronic solenoid valve is configured to control movement of liquid from the high pressured liquid source. It is preferable that the jet module is configured to propel liquids such as, for example, "bio-ink", hydrogel, nutrients, cell attachment medium, water and so forth.

There is also provided a 3D printer including a mobile structure for moving a plurality of printing modules, the mobile structure including a structural frame mounted on vertical rods in the 3D printer; a sub-frame mounted on secondary rods within the structural frame; and a bulk holder for containing a plurality of printing modules mounted on primary rods within the sub-frame. Preferably, the bulk holder includes individual compartments for placement of each printing module and is configured to move in X, Y and Z axes.

In another aspect, there is provided a biological safety cabinet for placement of a 3D printer, the cabinet including a transparent-type LCD panel which is configured to control the 3D printer and to display at least one of: parameters of the 3D printer and ambient parameters within the cabinet.

There is also provided a method of simultaneously printing a plurality of objects using a 3D printer with a plurality of printing modules. The method includes controlling a first printing module to carry out printing at a first position; and controlling a second printing module to carry out printing at a second position. It is advantageous that printing by the first and second printing modules are carried out simultaneously, and independently from one another.

In a final aspect, there is provided a method of printing an object made of at least two materials using a 3D printer with a plurality of printing modules. The method includes controlling a first printing module to carry out printing of a first portion of the object, the first portion being of a first material; and controlling a second printing module to carry out printing of a second portion of the object, the second portion being of a second material. Advantageously, printing by the first and second printing modules are carried out sequentially, and independently from one another. The second printing module can carry out printing of the second material at the same starting point as the first printing module but at a different layer or at a different starting point on a second portion of the object.

DESCRIPTION OF FIGURES

In order that the present invention may be fully understood and readily put into practical effect, there shall now be described by way of non-limitative example only preferred embodiments of the present invention, the description being with reference to the accompanying illustrative figures.

Figures 1(A) and 1(B) show perspective views of a first embodiment of a modular print head set up.

Figure 2 shows a photograph of the first embodiment of a modular print head set up.

Figure 3(a) shows a perspective view of a second embodiment of a modular print head set up and Figure 3(b) shows a photograph of the second embodiment.

Figure 4 shows a perspective view of a third embodiment of a modular print head set up.

Figure 5 shows a perspective view of a fourth embodiment of a modular print head set up. Figures 6(a) and 6(b) show perspective views of different extruder modules used in a modular print head set up.

Figures 7(A) and 7(B) show perspective views of a fifth embodiment of a modular print head set up.

Figures 8(A), 8(B) and 8(C) show samples of printed material on a substrate.

Figure 9 shows syringes used in a modular print head set up filled with different gel material.

Figure 10 shows a jet extruder usable with a modular print head set up.

Figure 11(a) show a photograph of removal of a syringe from a syringe-based extruder module.

Figure 11(b) shows an exemplary alternative configuration for securing a syringe.

Figure 12 shows a second perspective view of Figure 7(B). Figure 13 shows a perspective view for an enclosure usable with a 3D printer.

Figure 14 shows a photograph of a transparent-type LCD panel.

Figure 15(a) shows an exemplary bio-printed coronary artery.

Figure 15(b) shows an exemplary 3D printed luminescent micro-circuit.

Figure 16 shows an exemplary additional feature being incorporated into a printing module. Figure 17 shows an exemplary actuator configured to rotate a plurality of printing modules.

DESCRIPTION OF PREFERRED EMBODIMENTS The present invention details a plurality of ways for easy interchangeability of printing modules to enable a user to add, remove and swap individual extruders and/or print heads. This allows for greater flexibility, printing of different materials together such as plastics and bio-materials as well as easier maintenance. The present invention can be used on any form of extruders and 3D printers and is not limited to the filament-based extruders and the syringe-based extruders.

With reference to Figures 1 to 5, there is shown a 3D printer with three interchangeable extruder modules. It should be appreciated that more than three interchangeable extruder modules can be incorporated into the 3D printer in the manner described in the subsequent paragraphs, and the upper limit of the number of interchangeable extruder modules is dependent on physical space constraints of each 3D printer.

Referring to Figure 1 , there is shown a first embodiment of a modular print head set up 100 used in a 3D printer. In Figures 1 (A) and 1 (B) which show a back view and a frontal view respectively, the first embodiment employs the use of a plurality of slots 101 on a back plate 103, the back plate 103 being affixed to a 3D printer (not shown). The back plate 103 can also be integrated with the 3D printer and is not a separate component of the 3D printer. Each of the plurality of slots 101 enables placement of an extruder module 102, specifically a protruding handle 105 of the extruder module 102. It should be appreciated that even though the plurality of slots 101 are shown to be located at a first edge 106 of the back plate 103, the plurality of slots 101 need not be located at the first edge 106, and may be located anywhere at the back plate 103 in the form of openings in the back plate 103. The back plate 103 is attached to a main body of the 3D printer using screws, attached in a movable manner with track-based mechanisms or with other attachment mechanisms. It should be appreciated that each extruder module 102 includes an extruder 104, a printing nozzle/needle/tip (not shown), and the protruding handle 105. Figure 2 shows a photograph of the first embodiment of a modular print head set up with one of the plurality of slots 101 and the protruding handle 105 of the extruder module 02 being shown. It should be appreciated that each extruder module 102 need not include an extruder motor. The preceding statement applies to all extruder modules described in the following paragraphs. It should be appreciated that other printing mechanisms such as UV curing or inkjet printing can also be used in place of extruder modules.

Referring to Figure 3(a), there is shown a second embodiment of a modular print head set up 300. A back plate 303 includes at least one magnet 301 , each of the at least one magnet 301 having an exposed face. Each extruder module 302 includes at least one magnet of any shape/size (not shown), the at least one magnet of the extruder module 302 being configured to be attracted to the at least one magnet 301 of the back plate 303. In this regard, the user is able to mount the extruder module 302 to the back plate 303 using an attractive force between the magnets. It should be appreciated that the extruder module 302 includes an extruder 304, a printing nozzle/needle/tip (not shown), and the at least one magnet. Figure 3(b) shows a photograph of the second embodiment.

With reference to Figure 4, there is shown a third embodiment of a modular print head set up 400. A back plate 401 includes a first surface 410 covered by either a hooks or a loops side of a hooks-and-loops fastener. Each extruder module 402 includes a back surface 412 covered with another either the hooks or loops side of the hooks-and-loops fastener (depending on the side on the first surface 410). Placing the back surface 412 to the first surface 410 allows the extruder module 402 to be mounted to the back plate 401 at any position on the back plate 401. It should be appreciated that the extruder module 402 includes an extruder 404, a printing nozzle/needle/tip (not shown), and one side of a hooks-and-loops fastener at the back surface 412.

Referring to Figure 5, there is shown a fourth embodiment of a modular print head set up 500. A back plate 503 includes at least one rod holder block 502 on an interface surface 510. Each extruder module 504 includes at least one rod holder block 502 at a rear surface 512 of the extruder module 504. By aligning the rod holder blocks 502 of the back plate 503 and the extruder module 504, at least one rod 501 is slotted through holes of the rod holder blocks 502 to enable the extruder module 504 to be mounted to the back plate 503. If there are multiple rod holder blocks 502 on both the back plate 503 and the rear surface 512 of the extruder module 504, the user to adjust a height of the extruder module 504 if desired. It should be appreciated that the extruder module 502 includes an extruder 506, a printing nozzle/needle/tip (not shown), and at least one rod holder block 502 at the rear surface 512. It should be appreciated that while Figures 1 to 5 all show identical extruder modules adjacent to each other during use, such a configuration is not mandatory as shown in Figure 6. Figure 6 shows two syringe-based extruder modules 601 , 602 positioned adjacent to a filament-based extruder module 603 during use. Each of the syringes of the two syringe-based extruder modules 601 , 602 can hold a liquid or solution-based material such as cell suspension or agarose gel. In the set up as shown in Figure 6, each syringe-based extruder module 601 , 602 employs a 3ml NIPRO syringe and a 27G hypodermic needle. Referring to Figure 9, it is shown that the contents in each syringe of two syringe-based extruder modules 601 , 602 differ (based on their colour).

The set up shown in Figures 6(a) and 6(b) clearly demonstrates versatility in relation to the extruder modules which can be used. Control of each respective extruder module is carried out using a controlling unit such as a computer, or a microcontroller (such as ATmega2560). The aforementioned example microcontroller is able to support the connection of two additional extruders, three heaters, and three thermistors. A stepper motor for each syringe-based extruder module 601 , 602, 603, 604, 605, and 606 includes three IO contact pins to enable control of the stepper motor. In this regard, excluding the use of Liquid Crystal Displays (LCDs), SD card reader or any other extension devices, the example microcontroller board will have thirty six available pins to control twelve stepper motors (or twelve syringe-based extruder modules). Thus, it is possible to implement and operate two filament-based extruder modules (Each filament-based extruder requires three IO contact pins for a stepper motor, one IO contact pin for a thermistor, and one IO contact pin for a heater), together with up to twelve syringe-based extruder modules, or up to fourteen syringe-based extruder modules. With multiple extruder modules, each extruder's action and movement can be controlled by software or by numerical control programming languages such as G-code. This can lead to the laying down of different materials from different extruders. As mentioned earlier, different printing heads can be used other than extruder modules. Figures 7 and 12 show a fifth embodiment of a modular print head in a form of a mobile structure 700 set up for using twelve syringe-based extruder modules 701 within a 3D printer. It is possible to employ more than twelve syringe-based extruder modules 701 within a 3D printer, but doing so would entail increases in typical machine dimensions and typical power requirements to power the 3D printer. Figure 7(A) shows a bulk holder 710 for placement of the twelve syringe-based extruder modules 701. It should be appreciated that the bulk holder 710 includes individual compartments for convenient sliding placement of each syringe-based extruder module 701. The individual compartments 712 allow ease of swapping of each syringe-based extruder module 701. As shown in Figure 7(B), the bulk holder 710 is incorporated within a structural frame 702 which allows the bulk holder 710 to undergo motion along X, Y and Z axes. Timing belts 730, spiral rods and ball bearing screws are utilised to ensure movement of the bulk holder 710. The timing belts 730 are coupled to stepper motors 750, whereby the stepper motors 750 drive the timing belts 730. The bulk holder 710 is mounted to primary spiral rods 714 parallel to the X axis, the spiral rods 714 being within a sub-frame 716. The sub-frame 716 of the structural frame 702 is mounted to secondary spiral rods 718 parallel to the Y axis, the secondary spiral rods 718 being within the structural frame 702. The structural frame 702 is mounted to vertical rods 720 in the 3D printer. Even though Figure 7 shows only the use of syringe-based extruder modules 701 in the bulk holder 710, other types of extruder modules can also be used in the bulk holder 710. The type and number of extruder modules being used is dependent on a controlling unit used in the 3D printer, specifically a number of IO contact pins or communication ports on the controlling unit. It should be noted that a 3D printer which is set up to use multiple extruder modules in a manner as described in the preceding paragraphs is able to print a combination of non- biological materials (such as plastics, polymers, and so forth in filament or pellet form) and liquid-based materials (such as cell mixtures). There are times when different types of materials are required to be printed together, for example when printing a plastic scaffold and simultaneously, printing cells on the plastic scaffold. The non-biological materials and liquid- based materials can include non-biomaterials (such as, for example, plastics, ceramics, metals and so forth) and biomaterials (such as, for example, agarose, gel, cell suspensions and so forth). It should be appreciated that this multi-material printing uses at least two disparate types of materials, such as, for example, plastic-biomaterial, metal-biomaterial and so forth. The second extruder module can carry out printing of the second material at the same starting point as the first extruder module but at a different layer or at a different starting point on a second portion of the object.

Referring to Figure 8, samples of printed products using a set up as shown in Figure 6 are shown. Figure 8(A) shows an array of 3D printed dots of a gel substance. Figure 8(B) shows an array of 3D printed dots of water while Figure 8(C) shows an array of 3D printed lines of a gel substance. The printing of these products shown in Figure 8 results from use of 3D printing software and NC programming language. Figure 15(a) also shows another sample printed product of a bio-printed coronary artery 5500 (total diameter of < 5mm and a lumen diameter of < 2mm). Figure 15(b) shows a 3D printed luminescent micro-circuit. With reference to Figure 10, there is shown a jet extruder module 1000. The jet extruder module 100 is useful for liquids with low viscosity, and where the printed surface has to be fully covered quickly. It is fast, direct and convenient. It is also useful when the print surface is uneven where laying of materials by typical nozzle method may not work well. Given that the FDM way of depositing material is restricted in its resolution, using the jet extruder module 100 can enable printing at high resolution, such as in the application of printing micro patterns. Furthermore, the use of the jet extruder module 1000 can ensure that a relevant surface is appropriately covered with a desired thickness of the sprayed coat as parameters such as, for example, volume flow rate, solenoid valve opening, pressure reading and the like are controllable. This is desirable when carrying out multi-process printing as described in an earlier section. For example a first extruder prints a bioscaffold. Subsequently, the jet extruder module 100 sprays a fine coat of attachment material onto the bioscaffold, and another extruder prints cells on the scaffold. Furthermore, to achieve a truly 3D cell environment, the attachment material may also confer some sort of protection and structural support to the printed cells. When continuing from the last example, the jet extruder module 100 can coat the first layer of printed cells with the attachment material again, and continue printing a second layer of scaffold, sprayed with the attachment material, and printed with another layer of cells and the process can be repeated. The jet extruder module 1000 is configured to be capable of propelling liquids such as, for example, "bio-ink", hydrogel, nutrients, cell attachment medium, water and so forth. It should be appreciated that cell attachment medium includes, for example, liquids and gels. In the jet extruder module 000, there is an extended tube 1001 made of either brass or copper which extends along a length of the jet extruder module 1000. The extended tube 1001 allows passage of the liquid material which is being propelled. A spray nozzle 1002 of diameter between 0.1 mm to 0.3 mm is located at a first end 1005 of the extended tube 1001 where the liquid is aerosolised. A high-pressure canister (not shown) of the liquid is connected via a tube 1004 to an electronic solenoid valve 1003 that controls the movement of the liquid in the high- pressure liquid canister by either opening or closing its valve. The electronic solenoid valve 1003 is positioned at a second end 1006 of the extended tube 001. When the solenoid valve 1003 is opened electromechanically, the high pressure in the canister will propel the liquid through the tube 1004 into the extended tube 1001 and subsequently, propelled through the nozzle 1002. An application using the interchangeable extruder module set up as described in the preceding paragraphs is simultaneous printing of a plurality of objects. It is possible that a first extruder module is used to print a first object at a first area, while a second extruder module is used to print a second object simultaneously at a second area. Furthermore, the first and second extruder modules can also carry out printing using different materials. This can be carried out by customising numerical control programming language (eg. G-code) for controlling each extruder module. The capability of simultaneous printing of a plurality of objects allows array printing. Taking the twelve syringe-based extruder modules 701 of Figure 7 as an example, each syringe-based extruder module 701 can be programmed to print one type of material in a form of a cell line. Using numerical control programming language like G-code, it is possible to define a universal print path for all the syringe-based extruder modules 701 while each respective syringe contains a different material. Each of the syringe-based extruder modules 701 can print their respective material on a print surface such as, for example, a petri dish, a glass slide in any desired structure/pattern. As a single pass can print twelve different spots, that single pass can be repeated. This can lead to fabrication of an array of materials, suitable for high throughput applications such as diagnostics and drug screenings. Referring to Figure 11(a), there is shown an image of a removal/installation mechanism of a syringe from each syringe-based extruder module. Ease of removal/installation of the syringe is important as the syringe in each syringe-based extruder module is usually of single use. A "snap-on" method is provided whereby syringes 1110, 1110' are held in place by shaped pieces of plastic 1101 , 1101 ' respectively. The shaped pieces of plastic 1101 , 1101 ' are fitted in a receptor 1112, 1112' respectively. The shaped piece of plastic 1101 is then secured within the receptor 1112 by a metal strip 1102 using screws (the same is done for shaped piece of plastic 1101' but this is not shown in Figure 11 ). The metal strip 1102 ensures that the syringe 1110 is secured to the module such that a plunger rod is able to operate without movement of the syringe 1110. The metal strip 1102 need not be secured using screws. Other than screws, other securing mechanisms such as snap-on joints may also be used. Figure 11(b) shows an image of an alternative removal/installation mechanism of a syringe from each syringe-based extruder module which is easier to operate for gloved hands. The alternative mechanism comprises a knob 5000 which, when tightened, will push a block 5001 against a syringe to secure the syringe.

Referring to Figure 13, there is also provided a standalone Biological Safety Cabinet (BSC) 2000 for a 3D printer 3000, specifically bio-printers. The BSC 2000 is primarily for bio-printing applications, since cell and tissue culture work frequently require a sterile, and humidity/atmosphere/temperature-controlled environment to attain a required population and size. During printing from a bio-printer, it will mean removing the printed cells and transferring them to an incubator. This can be quite a hassle and may affect cell viability. With a built-in standalone enclosure including air circulators, UV lamps, HEPA and carbon filters, the working environment around the bio-printer can be kept sterile and suitable for cell culture tasks, correspondingly protecting the research objective and the user (during instances when toxic substances are involved). When temperature and carbon dioxide levels can be kept at constant conditions ideal for cell growth, this is beneficial for projects over extended durations. For example, a first layer of cells or tissue can be printed and be allowed to grow overnight. On the next day, another layer of cells/tissue will be printed again over the previous layer and the process is repeated. All this is done within the bio-printer 3000 encased in the BSC 2000, without movement of the printed cells/tissues which may disrupt placement and growth. A standalone BSC 2000 can be configured to accommodate a physical size of the bio-printer 3000, and is not restricted by existing available sizes.

Referring to Figure 14, there is shown an example of a transparent-type LCD panel 4000 of any size which can be installed either as a standalone unit or as part of the BSC 2000. This transparent-type LCD panel can be used to display parameters such as, for example, printing speed, printing temperature, ambience temperature, printing elapsed time, printing remaining time, pressure, humidity, C0₂ level, and so forth. It can also be a touchscreen for a user to control functions of the 3D printer 3000 within the BSC 2000. Since the transparent-type LCD panel is transparent, the user is able to see what is happening behind the transparent-type LCD panel, and can still serve as a display concurrently. The use of the transparent-type LCD panel not only enhances aesthetics of the BSC 2000, but also aids in operation of the 3D printer as the 3D printer is not obscured from view and can be continually/regularly monitored (so the user will not miss instances of printer failure like jamming) when using the transparent- type LCD panel. In addition, safety of the user is also ensured since the user is able to interface with the transparent-type LCD panel and avoid being in close proximity to moving parts of the 3D printer. The transparent-type LCD can be connected directly to a computer, the 3D printer 3000, or other microcomputer systems such as Arduino or Raspberry.

It should be appreciated that additional components can be integrated with individual printing modules to offer additional functions. Referring to Figure 16, a laser can be added to a bottom of the printing module to provide a visual guide 5600 for setting up and/or monitoring the experimental layout and physical movement of the printing head. A linear laser line (as shown) can be achieved by directing a laser beam through a clear solid rod made of plastic or glass. Alternatively, a laser grid can also be used for the purpose of accurate positioning and monitoring of printing progress. It should be appreciated that the adding of features is not limited to only at the bottom of a printing module. It should be noted that as the number of printing modules increases, the physical size of the 3D printer will also become larger. The printing modules are typically arranged in a row. For example if there are four modules, they will be lined in a row of adjacent printing modules which increases the size of the 3D printer. An alternative way is to arrange the modules in multiple rows instead of a single row. For example, four printing modules can be arranged in two rows of two modules. However, this results in poor accessibility to the printing modules at the back row and adversely affects procedures such as cleaning, swabbing and upgrading of the printing modules. Referring to Figure 17, there is shown an actuating device 5800 that is configured to hold/rotate a plurality of printing modules 5900 and can minimise a physical size of the 3D printer, while also enabling ease of access to the printing modules 5900 for different operations such as cleaning, swapping and upgrading. The actuating device 5800 can be operated manually or by a controlling unit such as a computer. The rotating movement of the actuating device 5800 can be provided by ball bearings, slot and track mechanism, and/or by motors and gears and other similar mechanisms. The actuating device 5800 is not restricted to being only top-mounted or for only four printing modules 5900, but can also be configured for any mounting position and any number of printing modules.

Whilst there have been described in the foregoing description preferred embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the present invention.

Claims

1. A 3D printer including:

a back plate; and

a plurality of printing modules, the plurality of printing modules being mounted to the back plate; wherein the each of the plurality of printing modules is mounted to the back plate using a mounting means selected from a group consisting of: fitment within a slot, magnetic attraction, hook-and-loop attachment, and interlocking of parts using a rigid structure.

2. The 3D printer of claim 1 , wherein each of the plurality of printing modules is of a type selected from a group consisting of: syringe-based extruder module, filament-based extruder module, UV curing module, inkjet printing module and jet extruder module.

3. The 3D printer of claim 2, wherein a syringe of the syringe-based extruder module is secured using a shaped piece of plastic fitted in a receptor, the shaped piece of plastic being further secured within the receptor using a rigid strip of material.

4. The 3D printer of claim 2, wherein a syringe of the syringe-based extruder module is secured using a knob which, when tightened, pushes a block against the syringe to secure the syringe.

5. The 3D printer of any one of claims 2 to 4, wherein the jet extruder module includes: an extended tube;

a nozzle at a first end of the extended tube;

an electronic solenoid valve at a second end of the extended tube; and

a tube connected to the electronic solenoid valve, the tube being connected to a high pressured liquid source.

6. The 3D printer of claim 5, wherein liquid is aerosolized at the first end of the extended tube.

7. The 3D printer of claim 5 or 6, wherein the electronic solenoid valve is configured to control movement of liquid from the high pressured liquid source.

8. The 3D printer of any one of claims 5 to 7, wherein the jet module is configured to propel liquids selected from a group selected from: "bio-ink", hydrogel, nutrients, cell attachment medium, and water.

9. The 3D printer of any one of claims 1 to 8, wherein the back plate is integrated with the 3D printer.

10. The 3D printer of any one of claims 1 to 8, wherein the back plate is affixed to the 3D printer.

1 1. The 3D printer of any one of claims 1 to 10, wherein the plurality of printing modules is configured to be rotatable.

12. The 3D printer of any one of claims 1 to 1 1 , wherein each of the plurality of printing modules is configured to be integrated with a laser or other feature.

13. A 3D printer including a mobile structure for moving a plurality of printing modules, the mobile structure including:

a structural frame mounted on vertical rods in the 3D printer;

a sub-frame mounted on secondary rods within the structural frame; and

a bulk holder for containing a plurality of printing modules mounted on primary rods within the sub-frame.

14. The 3D printer of claim 13, wherein the bulk holder includes individual compartments for placement of each printing module.

15. The 3D printer of claim 13 or 14, wherein the bulk holder is configured to move in X, Y and Z axes.

16. A biological safety cabinet for placement of a 3D printer, the cabinet including a transparent-type LCD panel which is configured to control the 3D printer and to display at least one of: parameters of the 3D printer and ambient parameters within the cabinet.

17. A method of simultaneously printing a plurality of objects using a 3D printer with a plurality of printing modules, the method including:

controlling a first printing module to carry out printing at a first position; and controlling a second printing module to carry out printing at a second position, wherein printing by the first and second extruder modules are carried out simultaneously, and independently from one another.

18. A method of printing an object made of at least two materials using a 3D printer with a plurality of printing modules, the method including:

controlling a first printing module to carry out printing of a first portion of the object, the first portion being of a first material; and

controlling a second printing module to carry out printing of a second portion of the object, the second portion being of a second material,

wherein printing by the first and second printing modules are carried out sequentially, and independently from one another.

19. A jet extruder module including:

an extended tube;

a nozzle at a first end of the extended tube;

an electronic solenoid valve at a second end of the extended tube; and

20. The jet extruder module of claim 19, wherein liquid is aerosolized at the first end of the extended tube.

21. The jet extruder module of claim 19 or 20, wherein the electronic solenoid valve is configured to control movement of liquid from the high pressured liquid source.

22. The jet extruder module of any one of claims 19 to 21 , wherein the jet module is configured to propel liquids selected from a group selected from: "bio-ink", hydrogel, nutrients, cell attachment medium, and water.