Micropigmentation

Cosmetic transdermal hair replication/Scalk Pigmentation (Micropigmentation): is more of a cosmetic procedure where ink is used to make the scalp appear that hair follicals exist where they did not before. 

Advantages and Disadvantages:

Some possible disadvantages of the procedure is that one may be stuck with a buzzed hairstyle because the cosmetic ink will not be able to make you look like you have long hairs. There is also really no information yet on whether the ink might be harful to the scalp or the effect of UV rays on the ink. Inquiry into the type of ink used is suggested (the Material Data Safety Sheet (MSDS) should be provided on the ink used). You may also want to ask what will happen if you loose more hair. Will you need more ink?

Companies:

 American Academy of Micropigmentation    Bosley micropigmentatio .  GoodLookInk .  ArtistryConcepts

How it is performed: 

SMP involved placing a strippled pattern of tattoo dots on the scalp which can create a normal appearing head of hair when no hair exists. (Rassman “Combining follicular unit extraction and scalp-micropigmentaiton for the cosmetic treatment of alopecias) 

Micropigmentation blends the technical components of a tatoo instrument and caefully selected pigments. Multiple sessions are recommended. The number of dots may be higher than 40k points in each session. The sessions are often long, extending up to 8 hours. If the pigment is placed only in the epidermis, the process will fail because the pigment will leak out within a few days after the procedure is done. If the pigment is placed too deep into the dermis, it will fail as it diffuses outside the confines of its original area of placement. (Rassman “Scalp Micropigmentation: a concealer for hair and scalp deformities” March 2015, 8(31))

Safety:

The FDA considers the inks used in tradermal tattoos, including permanent makeup, to be cosmetics. However, the actual practice of tattoing is regulated by local juridsdictions. Little is known about the chemical composition, adsorption, distribution, metabolism and excretion of inks.. Little information is available on short-term and long-term safety of the pigments, their carcinogenic potential, how they affect the cells that take up the inks and how the body responds to the interaction of ultraviolet light with the inks. It is known that some tattoos fade or turn color when they are exposed to light and that some pigments migrate from the tattoo site to the body’s lymph nodes. The long-term health singificance of this is unclear. (Rassman “Scalp Micropigmentation: a concealer for hair and scalp deformities” March 2015, 8(31))

Instruction:

jhonjhon

3-D Printing

Companies:  Form labs  Carbon3D

Stereolithography (SLA):

SLA works by concentrating a beam of ultraviolet light onto the surface of a vat filled with liquid phtocurable resin. The UV laser drawns out the 3D model as the light hits the resin one think layer at a time, hardening that slice of the soon to be 3D model. The high resolution 3 D model can eventually be lifted out of the vat. See 3D Systems

Fused Deposition Modeling (FDM) (material extrusion): 

FDM works by extruding a stream of melted thermoplastic materials to form layers. Each layer stacks on top of and fuses with the previous layer as the material hardens almost instantaneously after leaving the extrusion nozzle. Most FDM printers print with ABS plastic as well as polyactic acid (PLA, a biodegradable polymer. See Stratasys 

With respect to tissue engineering, one print head can be used to depoist a hydrogel or biodegradable thermoplastic such as polycaprolactone while a second print head depoists a cell supsension. 

PolyJet photopolymer (Inkjet bioprinting): 

Inkjet bioprinting works similar to a traditional inkjet printer by depositing ink. A photpolymer liquid is precisely jetted out and then hardened with a UV light. The layers are stacked successively so that various materials and colors are incorporated into single prints. See Stratasys

Inject bioprinting uses the same type of print heads found in 2D inkjet printers mounted on a three-axis gantry. The print heads have ink reservoirs and a very small nozzle thorugh which small droplets are ejected using thermal excitation or a pressure pulse deliverd by a piezelectric component. 

Thermal print heads work by applying a quick heat pulse to a chamber closest to the nozzle, creating a vapor bubble. Pressure from that vapor bubble jects a small droplet of ink. 

Selective Laser Sintering (SLS): 

SLS works similar to SLA, but instead of liquid photopolymer in a vat, there are powdered materials, such as polystyrene, ceramics, glass, nylon, and metals including steel, titanium, aluminum and silver. When the laser hits the powder, the powder is fused at that point (sintered). The lack of any requirement for any support strucutre with SL:S is an advantage over FDM/FFF and SLA. All unsintered powder reamins as is, and becomes a support structure for the object. The lack of necessity for any support strucutre with SLS is an advantage over FDM/FFF and SLA.

Selective Laser Meling (SLM): is similar to SLS but it melts the powder rather than just fusing the powder granules at a lower temerpature.

Syringe extrusion: uses syringe extruders to print almost any type of materials which has a soft viscosity including cement, silicone and clay.

Electronic (“E”)-Ink

E InkE Ink    Think Geek (has a  programmable tattoo system using subdermal implants)  

Applications

Leading Edge Aviation Propulsion (LEAP): is being used by companies like GE and the French company Snecma in the generation of anext generation aircraft engines.

Hearing aids and teeth aligners: Because of its scalability and excellent resolution, sterolithography is used to fabricate nearly all in the ear hearing aids and millions of Invasalign teeth aligners.