Since the first case of COVID-19 in Europe was detected on January 24, concern about the exponential transmission of the virus has been on everyone's mind. In the field of engineering, there are different working groups with whom CIM-UPC is actively working on the design, validation, manufacture and distribution of respirators, masks or protective visors. But it is also very important to prevent new infections. And this is where it appears the inherent risk of opening and closing doors of common areas of buildings, hospitals, work centers or shop with the hands. According to a recent study published by the New England Journal of Medicine, SARS-CoV-2 is capable of maintaining its infectious properties for hours, and even days, on certain materials such as steel. The engineers at CIM UPC began to analyse the different alternatives available on the market to open the doors without using the hands and realized that none were easy enough to assemble, nor did they adapt to the different types of handles and that, in general, they required special elements being difficult to procure. So they got down to work. The final outcome, after a hard week working with different designs and prototypes, is the Arm Door Opener. It consists of a single piece that can be manufactured in less than 4 hours with any desktop 3D printer and can easily be assembled with only 3 cable ties. This design has been made in two versions for doors that open to the left and to the right and the assembly is carried out in less than a minute with the help of only 3 cable ties and without the need for any training or technical expertise. This digital design, materialised by any 3D printer, can be replicated worldwide, which can help minimise the risk of COVID-19 contagion. At the moment, the first large batch will be manufactured at the assembly centre of BCN3D for desktop 3D printers, spin-off of CIM-UPC, on the UPC campus in Castelldefels (Barcelona). Currently, BCN3D is a leading company in its sector that has made available to the fight against COVID all their 3D printers dedicated to producing its components. There are more than 60 3dprinters. The production of these openers is also foreseen in the Barcelona Local Manufacturing Athenaeums (public Fablabs of the Barcelona City Council) and in other centres, such as the MakerSpace in Santa Perpètua de Mogoda. All them have participated in the co-design of the opener, so that the more the merrier in order to distribute them. All the digital information for anyone to reproduce the Arm Door Opener can be downloaded for free from CIM-UPC website, as well as from the main 3D file repositories that are available on the net. If globalization has spread the virus, it will also be able to facilitate its defeat thanks to network innovation and universal access to CAD tools and additive manufacturing. This is a collective success in a situation of confinement, as long as most of the participants in the project are working at home and use their own 3D printer. With this contribution, CIM-UPC, the UPC technology centre, gives its answer to a need that, due to current health crises, had remained at a second level of priority, but which is equally important. And CIM-UPC team continues working, without a break, in search of other solutions that could help in the fight against this virus. https://www.youtube.com/watch?v=wg9fRajdEFY&feature=youtu.be