Light-based additive manufacturing holds great potential in the field of bioprinting due to its exceptional spatial resolution,enabling the reconstruction of intricate tissue structures.However,printing through biolog...Light-based additive manufacturing holds great potential in the field of bioprinting due to its exceptional spatial resolution,enabling the reconstruction of intricate tissue structures.However,printing through biological tissues is severely limited due to the strong optical scattering within the tissues.The propagation of light is scrambled to form random speckle patterns,making it impossible to print features at the diffraction-limited size with conventional printing approaches.The poor tissue penetration depth of ultra-violet or blue light,which is commonly used to trigger photopolymerization,further limits the fabrication of high cell-density tissue constructs.Recently,several strategies based on wavefront shaping have been developed to manipulate the light and refocus it inside scattering media to a diffraction-limited spot.In this study,we present a high-resolution additive manufacturing technique using upconversion nanoparticles and a wavefront shaping method that does not require measurement from an invasive detector,i.e.,it is a non-invasive technique.Upconversion nanoparticles convert near-infrared light to ultraviolet and visible light.The ultraviolet light serves as a light source for photopolymerization and the visible light as a guide star for digital light shaping.The incident light pattern is manipulated using the feedback information of the guide star to focus light through the tissue.In this way,we experimentally demonstrate that near-infrared light can be non-invasively focused through a strongly scattering medium.By exploiting the optical memory effect,we further demonstrate micro-meter resolution additive manufacturing through highly scattering media such as a 300-μm-thick chicken breast.This study provides a concept of high-resolution additive manufacturing through turbid media with potential application in tissue engineering.展开更多
3D printing has revolutionized the manufacturing of volumetric components and structures for various fields.Thanks to the advent of photocurable resins,several fully volumetric light-based techniques have been recentl...3D printing has revolutionized the manufacturing of volumetric components and structures for various fields.Thanks to the advent of photocurable resins,several fully volumetric light-based techniques have been recently developed to push further the current limitations of 3D printing.Although fast,this new generation of printers cannot fabricate objects whose typical size exceeds the centimeter without severely affecting the final resolution.Based on tomographic volumetric additive manufacturing,we propose a method for volumetric helical additive manufacturing(VHAM)multi-cm scale structures without magnifying the projected patterns.It consists of illuminating the photoresist while the latter follows a helical motion.This movement allows to increase the printable object’s height.Additionally,we off-center the modulator used for projecting the light patterns to double the object’s lateral size.We demonstrate experimentally the interest of using these two tricks for printing larger objects(up to 3 cm×3 cm×5 cm)with fine details(650μm)and short print time(<10 min).展开更多
基金funding from the Swiss National Science Foundation under project number 196971-“Light based Volumetric printing in scattering resins.”。
文摘Light-based additive manufacturing holds great potential in the field of bioprinting due to its exceptional spatial resolution,enabling the reconstruction of intricate tissue structures.However,printing through biological tissues is severely limited due to the strong optical scattering within the tissues.The propagation of light is scrambled to form random speckle patterns,making it impossible to print features at the diffraction-limited size with conventional printing approaches.The poor tissue penetration depth of ultra-violet or blue light,which is commonly used to trigger photopolymerization,further limits the fabrication of high cell-density tissue constructs.Recently,several strategies based on wavefront shaping have been developed to manipulate the light and refocus it inside scattering media to a diffraction-limited spot.In this study,we present a high-resolution additive manufacturing technique using upconversion nanoparticles and a wavefront shaping method that does not require measurement from an invasive detector,i.e.,it is a non-invasive technique.Upconversion nanoparticles convert near-infrared light to ultraviolet and visible light.The ultraviolet light serves as a light source for photopolymerization and the visible light as a guide star for digital light shaping.The incident light pattern is manipulated using the feedback information of the guide star to focus light through the tissue.In this way,we experimentally demonstrate that near-infrared light can be non-invasively focused through a strongly scattering medium.By exploiting the optical memory effect,we further demonstrate micro-meter resolution additive manufacturing through highly scattering media such as a 300-μm-thick chicken breast.This study provides a concept of high-resolution additive manufacturing through turbid media with potential application in tissue engineering.
基金the Swiss National Science Foundation under project number 196971-“Light based Volumetric printing in scattering resins”European Union’s Horizon 2020 research and innovation programme under grant agreement No 964497the free or open-source tools(and their contributors)which were used in this work,including Tinkercad.com,FreeCADweb.org,Inkscape.org,Python.org,PyTorch.org,and Thingiverse.com.
文摘3D printing has revolutionized the manufacturing of volumetric components and structures for various fields.Thanks to the advent of photocurable resins,several fully volumetric light-based techniques have been recently developed to push further the current limitations of 3D printing.Although fast,this new generation of printers cannot fabricate objects whose typical size exceeds the centimeter without severely affecting the final resolution.Based on tomographic volumetric additive manufacturing,we propose a method for volumetric helical additive manufacturing(VHAM)multi-cm scale structures without magnifying the projected patterns.It consists of illuminating the photoresist while the latter follows a helical motion.This movement allows to increase the printable object’s height.Additionally,we off-center the modulator used for projecting the light patterns to double the object’s lateral size.We demonstrate experimentally the interest of using these two tricks for printing larger objects(up to 3 cm×3 cm×5 cm)with fine details(650μm)and short print time(<10 min).
