Patent ID: 11872746
Assignee: ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
Field: Other special machines (Mechanical engineering)
Classification: CPC B  C | IPC B  C

Claim 0:
1. A method of printing a three-dimensional article comprising:
computing a sequence of back-projections describing the three-dimensional article to be formed from different orientation angles of said article,
defining a sequence of patterns of curing light using said back-projections, and
irradiating with each of said patterns of curing light at the respective corresponding orientation angle and according to the defined sequence of patterns of curing light a liquid photoresponsive material, or a thermoresponsive gel formed from a liquid photoresponsive material with thermoresponsive gelation properties, that is capable of alteration of a material phase of the liquid photoresponsive material or the thermoresponsive gel upon irradiation by curing light, thereby selectively creating a three-dimensional distribution of alterations within the liquid photoresponsive material which physically reproduces said three-dimensional article, thereby creating the three-dimensional article, and
separating said three-dimensional article from the thermoresponsive gel by forming a liquid from the thermoresponsive gel and filtering the three-dimensional article from the liquid thermoresponsive material,
wherein the liquid photoresponsive material or the thermoresponsive gel comprises a first photoinitiator in an amount such that an optical depth of penetration of the curing light is larger than a fifth of a width of the three-dimensional article,
the liquid photoresponsive material has an optical transparency of at least 50% transmission between 350 nm and 450 nm at a thickness of the width of the three-dimensional article, or alternatively the thermoresponsive gel has an optical transparency of at least 50% transmission between 350 nm and 850 nm at a thickness of the width of the three-dimensional article,
the liquid photoresponsive material or the thermoresponsive gel has a scattering length larger than the width of the three-dimensional article,
the liquid photoresponsive material, at a temperature of 25° C., has a dynamic viscosity between 2000 and 50000 centipoises, or alternatively the thermoresponsive gel has a liquification or gelation temperature between 0° C. and 40° C., and
the three-dimensional article is formed in about 1 to 60 seconds.