{'fraction_non_alphanumeric': 0.008174386920980926, 'fraction_numerical': 0.004541326067211626, 'mean_word_length': 5.719512195121951, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
New method for reducing viscosity and shear stress in hydrogel 3D printing via multidimension vibration

Abstract Microextrusion 3D bioprinting is a comparatively easy method to fabricate structures in tissue engineering. But high viscosity and wall shear stress in the tube and nozzle often lead to low cell survival rate of printed tissue. To reduce the viscosity and shear stress of materials in biological 3D printing, a multidimension microvibration assisted hydrogel 3D printing method was proposed. The compliant mechanism driven by piezoceramic was applied to 3D printing of hydrogels. The shear stress and viscosity of hydrogels could be effectively reduced by multidimension microvibration. Simulation analysis of the extrusion device was carried out to study the influence of vibration parameters on viscosity and shear stress, and optimized multidimension vibration forms and vibration parameters were selected for experiments. The experiment results show that multidimension microvibration can effectively reduce the viscosity of hydrogels and improve printing resolution and print speed.