Capillary networks are the smallest and most intricate blood vessels in the body, playing a crucial role in the exchange of oxygen, nutrients, and waste between blood and body cells. These networks connect smaller arteries to veins and are essential for maintaining the health of tissues. In the United States, researchers have made a breakthrough in creating artificial capillary networks using a new 3D printing method. This innovation could significantly improve the success of organ transplants by enabling the creation of more lifelike artificial organs. In May 2026, a team from the Department of Aerospace and Mechanical Engineering at the University of Notre-Dame-du-Lac introduced a novel 3D printing technique in the journal Nature Chemical Engineering. Their method allows for the production of blood capillaries with diameters smaller than 10 micrometers—about the width of a human hair divided into 1,000 parts. This achievement addresses a major challenge in artificial organ development: vascularization. Without functioning capillaries, cells in the middle of a 3D-printed organ often die due to a lack of oxygen and nutrients. The technique combines biology, mechanical engineering, and artificial intelligence to overcome the limitations of traditional methods. It starts with extrusion printing, which deposits a soft, gel-like matrix that mimics the structure of natural tissues. Next, Aerosol Jet Printing (AJP) is used to create micro-channels with extreme precision. Artificial intelligence plays a key role by adjusting the flow of biological ink and coating gas in real time, ensuring the ideal vessel diameter is achieved without the need for lengthy trial and error. According to the study, recreating the complex structure of natural vascular networks at the capillary level has long been a major challenge in organ manufacturing. This method achieves precision at the micrometer level while maintaining over 90% cellular viability, bringing scientists closer to developing fully functional organs for human transplants. The potential applications extend beyond organ transplants to include regenerative medicine, tissue engineering, and drug discovery. With a global shortage of organs, where only about 10% of transplant requests are met, this innovation could offer a promising solution. In the United States alone, over 100,000 people are waiting for a transplant, and several patients die each day due to the lack of available organs.