Solid freeform technique

Derived from standard desktop printers, drop-on-demand techniques, such as electrohydrodynamic jet (e-jet) printing, solid freeform fabrication (SFF), or piezoelectric inkjet printing, are among a few notable examples of rapid prototyping techniques that have been developed to pattern biomaterials. With the incorporation of a user friendly computer interface, these techniques have been employed to process a number of multiplexed, biomaterial constructs without the use of masks, stamps, or any other time consuming processing equipment. The design of such constructs with minimal feature sizes in the microliter to picoliter resolution has been demonstrated and will be discussed below. 

Scaffolds can be fabricated by using different types of methodologies such as fiber bonding, salt leaching, gas-induced foaming, phase separation, electrospinning, solid freeform fabrication, and molecular self assembly [15, 17]. Some of the fabrication techniques are discussed below. 

Rapid prototyping (RP) or solid freeform fabrication (SFF) is a relatively recent approach to forming ceramic components. There are various forms of RP techniques, but they are based on a common principle a computer directly controls the shaping process by accessing computer-aided design (CAD) files. We can thus use RP to form a 3D component without the use of a die or a mold. RP techniques are used commercially for fabrication of parts from polymers for design verification and form-and-fit applications these techniques have more recently been applied to forming parts out of ceramics. 

Example Solid freeform fabrication (SFF) techniques such as selective laser melting (SLM) and sintering (SLS) are often prized for being much cleaner than conventional machining processes and being able to fabricate products with minimum waste (e.g., Bourell et al. 2009). 

The solid freeform fabrication of thin-walled ceramic structures can be achieved using an electrohydrodynamic jet technique (32). This technique was used to deposit 100 layers of a 10 vol% zirconia suspension. Thus, a wall of a thickness of 100 pm was freeformed. 

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