One of the most interesting field in which the 3D Printing is being considered is the fabrication of biocompatible devices and parts for a medical applications. For that I am interesting in knowing what technique are used for the fabrication of splints or cast used for the immobilization of human body part, also which material is compatible with this technique?
What's the best printing technique to produce splints (a device to immobilize a body part)?
1$\begingroup$ I am pretty sure any material and manufacturing process that needs to be used in a medical environment is subject to tight regulations that are possibly country specific. Materials like lead - commonly found in FDM printers parts that come into contact with the filament - are potent neurotoxins, and exposure to some additives used in resins and plastic polymers is also considered a health hazard. So beware that even if the answer may turn out to be "FDM printing PLA", both the printer and the PLA may be specialised "medical grade" ones. $\endgroup$– macFeb 3, 2018 at 4:23
$\begingroup$ @Mac please say more about "lead commonly found in FDM printer parts". This is news to me $\endgroup$– OyaMistJul 6, 2018 at 15:22
3$\begingroup$ Lead is often used in metal alloys to alter their physical properties. For example, it is very common to find it in machined brass parts (a nozzle is precisely that) as it increase its machineability. Basically you should consider any metal part touching the filament (cog wheel, hot end, nozzle, ...) as a potential source of contamination unless you are positive of the contrary. $\endgroup$– macJul 13, 2018 at 6:20
2$\begingroup$ I'm voting to close this question as off-topic because it is a) too broad and b) a list question asking for 1) techniques 2) materials $\endgroup$– TrishDec 12, 2018 at 9:42
1$\begingroup$ The photo you posted is of a cast that was printed using Nylon and FDM, or the extrusion method. Source: evilldesign.com/cortex $\endgroup$– Tyler SFeb 3, 2019 at 21:41
For anything where there is an open or bandaged wound, you should NOT use 3D printing, and should use sterilized medical equipment to prevent infection and heavy metals infiltrating the bloodstream.
SLA/SLS 3D printing may be the best option for replicating the complex structure of the splint you have pictured above, as FDM printers have difficulty reproducing those structures.
However, FDM printing CAN reproduce it, and generally FDM printers have access to a wider variety of materials of which models can be printed with, so they may be the best option overall.
For something to immobilize a body part that has been broken, you may want to use a stiff material such as ABS or Carbon Fibre, However PLA may work still in these cases.
As for something to support a body part, Flexible or Semi-Flexible materials may be desired, such as Ninjaflex (TPU), Nylon.
As a disclaimer:
I am not a medical professional, This is not medical advice, please consult a properly licenced medical professional first before using 3D printing to solve a medical ailment.
$\begingroup$ PLA is very stiff, moreso than ABS I believe. That means it's also more brittle though. $\endgroup$ Aug 30, 2019 at 1:10
$\begingroup$ note that you could arguably print the splint flat, then heat it some in an oven and wrap it around the bandage, creating a perfect form fit. $\endgroup$– TrishAug 30, 2019 at 8:22
$\begingroup$ That could work aswell, i never thought of that $\endgroup$ Aug 30, 2019 at 20:36