printed mold for silicone hot liquid pump (artificial heart) and pinch valve

thingiverse

the tpe mold does not work. it seems the silicone will not cure when in contact with tpe. so printed the mold with abs and hips. need to break the inner part of the mold. the outer part is re-usable. the heart chambers can be driven with a servo or SMA. servo use far less power hungry and offers more control. the servo is placed in between 2 of the pumps (with a one way valve on each end), this will make a 2-chamber 4-valve heart. i made a vacuum chamber out of a 12v dc car air pump and a glass jar for the silicone. better than none. update 16th Oct 2014: the duck bill valve works but not fell short of expectation. made valve1016, a design copied from the pulmonary semilunar valve of a human heart. can drill a few hole through the inner part or the mold to form silicone chordae tendineae if very soft molding silicone is used or larger servo is used. i use 4kg/cm servo. update 18thOct2014: heartvalve1016 works, performance not ideal. wall too thin. valve edge design fault (inside out). updated with heartvalve1018 end connector section for SMA arteryend1017 uploaded update 18 Nov 2014 on the request from breye, uplaoded more pic. new heart valve. put the valve on each end, facing the same direction, clue with silicon. unless you what to try to grown tissues as lining or use the thing as support for growing tissues, or use part of organs like intestine or make one cavity with types of tissues, and drive with servo or low temp SMA, a rotary type of pump might be a better option. but i believe low temp (around 40 degree c) SMA with none contact (inductive) activation is a viable idea and worth trying for artificial hearts. comparing with motors, SMA is a lot lot lighter and smaller, maintenance free and last for ever (used within temperature and stress range) while a motor will eventually worn out . the down side is sma will drain a battery faster than motors for the same work. since i do not have a vacuum or compress chamber, i have difficulty pouring bubble-free silicone parts. I printed one with tpe, great, but can not match the heat resistance property of silicone. and worse, i have found out the silicone will not cure when in contact with tpe. i still think the silicone heart pump would be a better choice for implants. i do not want to invest in vacuum or compress chamber for silicone, so i am milling my high temp pump with aluminium or delrin. unlike the heart pump, these rotary pumps are not in one piece, requiring seals, not fully sealed like a heart pump, will not be as durable, however will serve my project well for now. hope this will help, Breye.