Haptic Interface Force Sensing

Background: In a haptic interface, the human subject interacts with a virtual display which he or she can modify based on visual, tactile, or kinesthetic feedback. In haptics applications, a properly-fitting mechanism is required to allow the user to push, squeeze, or grasp an object.

Challenge: Developing a small, light-weight, force-sensing equipped device which can easily be maneuvered by the user and which will encourage “natural exploration” of objects.

Solution: Researchers at Universidad Politecnica de Madrid integrated FlexiForce™ force sensors into a lightweight (8 grams) thimble device, which fits over the user’s fingers. The geometry of the device is quite similar to the human finger. Due to its construction, it provides more freedom and natural exploration of objects than some traditional haptic end effectors. FlexiForce sensors are used to estimate the forces exerted by the user during various manipulations. FlexiForce was selected due to its thinness (0.2mm), light weight, and performance specifications, particularly its repeatability, which is ± 2.5%.