Researchers at Northwestern University and Tel Aviv University have made significant strides in developing a cost-effective solution for advanced robotic touch sensors. This advancement addresses a key challenge in the field of robotics - the insulation layer within robotic skin that affects the accuracy and repeatability of touch sensor measurements.
The study, recently published in the journal Advanced Electronic Materials, reveals that the insulating layer found in inexpensive silicon rubber composites used for making robotic skin hinders direct electrical contact between the sensing polymer and monitoring surface electrodes. By removing this layer, the researchers have managed to improve the sensors' accuracy, enabling robots to mimic the nuanced human ability to sense the curves and edges of objects.
Matthew Grayson, a professor of electrical and computer engineering at Northwestern University, explained the common oversight in scientific studies, "A lot of scientists misunderstand their sensor response because they lump together the behavior of the contacts with the behavior of the sensor material, resulting in inconsistent data," he said. He highlighted the importance of distinguishing the problems associated with electrical contacts in sensor responses to ensure reliable and reproducible scientific outcomes.
The interdisciplinary team of electrical engineers and polymer materials scientists used electrically-conducting fillers like carbon nanotubes to enhance the elastomer materials of robotic skins, while also addressing the thin insulating layer that affects electrical contact. Co-author Noa Lachman, a professor at Tel Aviv University, remarked, "All interesting things happen at the interface," noting the importance of collaboration between different scientific disciplines.
Grayson emphasized the necessity of multidisciplinary collaboration, particularly with Tel Aviv University, stating, "That’s why our collaboration with Tel Aviv is essential – they know the materials science that we don’t know.” The study advocates for rigorous quality checks in sensor research, calling the scientific community to higher standards of reproducibility.
The research received support from various institutions, including the U.S. National Science Foundation, Northwestern University's Crown Family Fund, Tel Aviv University, and the U.S.-Israel Binational Science Foundation, showcasing a strong international partnership.