Biofabrication technologies, including stereolithography and extrusion‐based printing, are revolutionizing the creation of complex engineered tissues. The current paradigm in bioprinting relies on the additive layer‐by‐layer deposition and assembly of repetitive building blocks, typically cell‐laden hydrogel fibers or voxels, single cells, or cellular aggregates. The scalability of these additive manufacturing technologies is limited by their printing velocity, as lengthy biofabrication processes impair cell functionality. Overcoming such limitations, the volumetric bioprinting of clinically relevant sized, anatomically shaped constructs, in a time frame ranging from seconds to tens of seconds is described. An optical‐tomography‐inspired printing approach, based on visible light projection, is developed to generate cell‐laden tissue constructs with high viability (>85%) from gelatin‐based photoresponsive hydrogels. Free‐form architectures, difficult to reproduce with conventional printing, are obtained, including anatomically correct trabecular bone models with embedded angiogenic sprouts and meniscal grafts. The latter undergoes maturation in vitro as the bioprinted chondroprogenitor cells synthesize neo‐fibrocartilage matrix. Moreover, free‐floating structures are generated, as demonstrated by printing functional hydrogel‐based ball‐and‐cage fluidic valves. Volumetric bioprinting permits the creation of geometrically complex, centimeter‐scale constructs at an unprecedented printing velocity, opening new avenues for upscaling the production of hydrogel‐based constructs and for their application in tissue engineering, regenerative medicine, and soft robotics.

In tomographic volumetric additive manufacturing, an entire three-dimensional object is simultaneously solidified by irradiating a liquid photopolymer volume from multiple angles with dynamic light patterns. Though tomographic additive manufacturing has the potential to produce complex parts with a higher throughput and a wider range of printable materials than layer-by-layer additive manufacturing, its resolution currently remains limited to 300 µm. Here, we show that a low-étendue illumination system enables the production of highresolution features. We further demonstrate an integrated feedback system to accurately control the photopolymerization kinetics over the entire build volume and improve the geometric fidelity of the object solidification. Hard and soft centimeter-scale parts are produced in less than 30 seconds with 80 µm positive and 500 µm negative features, thus demonstrating that tomographic additive manufacturing is potentially suitable for the ultrafast fabrication of advanced and functional constructs.

We demonstrate for the first time to our knowledge a digital phase conjugation technique for generating a sharp focus point at the end of a multimode optical fiber. A sharp focus with a contrast of 1800 is experimentally obtained at the tip of a 105 μm core multimode fiber. Scanning of the focal point is also demonstrated by digital means. Effects from illumination and fiber bending are addressed.

We use Deep Neural Networks (DNNs) to classify and reconstruct a large database of handwritten digits from the intensity of the speckle patterns that result after the images propagated through multimode fibers (MMF). Images transmitted through fibers with up to 1km length were recovered. The ability of the network to recognize the input degraded with fiber length but the performance could be enhanced if the neural networks were trained to first reconstruct the image and then classify it rather than classify it directly from the speckle intensity.

We propose and experimentally demonstrate an ultra-thin rigid endoscope (450 μm diameter) based on a passive multimode optical fiber. We use digital phase conjugation to overcome the modal scrambling of the fiber to tightly focus and scan the laser light at its distal end. By exploiting the maximum number of modes available, sub-micron resolution, high quality fluorescence images of neuronal cells were acquired. The imaging system is evaluated in terms of fluorescence collection efficiency, resolution and field of view. The small diameter of the proposed endoscope, along with its high quality images offer an opportunity for minimally invasive medical endoscopic imaging and diagnosis based on cellular phenotype via direct tissue penetration.