(671d) Poroelastic Mechano-Sensing Soft Robots

Modern society relies on automation and robotics to accomplish a wide variety of menial, hazardous, and finely monitored tasks. While solving a myriad of human’s problems, conventional “hard” robots lack a few key features: they are not easily adaptable, suffer high energy costs, and often cause injuries when sharing space with humans. In contrast to conventional robots, soft robots are made of highly stretchable, easy to shape materials, making them prime candidates to complete challenges insurmountable to conventional robots. Yet, soft robots also suffer from some limitations, one of them being the lack of mechanosensing abilities. Recent studies have investigated different ways to impart mechanosensing abilities to soft robots by using electro-sensing and optical-sensing methods. These methods are very promising but suffer from a few drawbacks, such as sensitivity density or signal coupling, that prevent their widespread adoption. To address these issues, we chose to design a smart skin transmitting information solely using poroelasticity. We designed a pad made of a PDMS hollow bloc filled with water, that we implemented on a homemade 3D printed arm, and connected to a pressure sensor. This allowed us to apply a deformation to an object and measure the associated pressure increase. This measurement, used in the context of contact mechanics, allowed us to extract the effective Young’s modulus of the object. This kind of approach can be very useful to design mechanosensitive soft robots for less invasive surgical applications where liquids and devices sensitive to electrical currents are nearby.