For a long time, sensors have been a resource used in different areas, either to measure the behavior or performance of an object, or of a particular process.
In this sense, a new technique emerges based on 3D printing: hydrogel-based sensors that can be implanted on the surface of organs such as the lungs, providing them with the ability to adapt to the movement of these when expanding and contracting. The initiative has been developed by researchers from the University of Minnesota who received funding from the NIBIB to launch the project.
Dr. Michael McAlpine, professor of mechanical engineering, leads the research team of mechanical and computer engineers. In reference to the Alpine project, he stated the following:
Coupled with the ability of a robot to help a surgeon remove a tumor from a lung, for example, this technology could 3D print a sensor on the surface of the lung to monitor its function during and after the procedure.
Through this cutting-edge technology, the researchers hope that over time the 3D printing of some devices both inside and outside the human body will become possible, and that these will be functional.
Some examples contemplate the use of electrodes programmed to maintain interaction with the nervous system as a measure to address pain conditions that may arise, as well as bio-scaffolds with cells that allow tissue regeneration, skin grafts and, finally, the implementation of surgical queues.
For his part, the director of the NIB program in binic and robotic systems, Dr. Michael wolfson pointed out the following in reference to the work carried out by McAlpine and the team:
They consistently identify biomedical problems that need technological solutions and then design and build sophisticated systems to meet the need.  And because this research is not just about innovative engineering, it also shows that the technology works in realistic biological systems.
Origin of this technique
The achievement of this technology lies in the technique of motion capture, similar to that used in the production of movies and video games.
In the case of cinema, motion capture allows you to track moving elements within a scene so that the necessary special effects can then be applied, either on the actors or on the environment.
Through this procedure it was possible to further optimize the 3D printing and put it to the test by successfully printing a sensor on an expanding living tissue without causing damage to the organ.
After being subjected to a series of experiments on a balloon that was inflated and deflated, the next step to be taken with the sensors was to print them on the lung of an animal while it was kept in operation with insufflated air that made it pulse rhythmically.
Next, a special hydrogel embedded with surrounding electrodes was printed to obtain an electrical impedance tomography (EIT) sensory map.
The end result was a device with the ability to stretch and adapt to the movement of the surface of the lung in which it was implanted, being then registered by the sensor and transmitted electronically as part of a process of monitoring in real time of the surface tension. of the lung as it expands and contracts.
In reference to this, McAlpine stated:
Measuring the flexibility of the lung with the EIT sensor is just one example of remotely measuring the health of an organ using a sensor imprinted on its surface.  We envision the development of different types of sensors that could be adapted to different organs, such as a sensor imprinted on a human heart to monitor cardiac function.
It is thought that this technology could be a very useful tool when it comes to caring for patients with COVID-19. Based on this McAlpine expressed:
We are learning a lot about the long-lasting effects of COVID-19 on the human body  Technology like this could be used to monitor changes in respiratory function during and after coronavirus infection.