But if you press harder, you may notice a second way of sensing the touch: through your knuckles and other joints. That sensation–a feeling of torque, to use the robotics jargon–is exactly what the researchers have re-created in their new system. Their robotic arm contains six sensors, each of which can register even incredibly small amounts of pressure against any section of the device. After precisely measuring the amount and angle of that force, a series of algorithms can then map where a person is touching the robot and analyze what exactly they're trying to communicate. For example, a person could draw letters or numbers anywhere on the robotic arm's surface with a finger, and the robot could interpret directions from those movements. Any part of the robot could also be used as a virtual button.