  Robots are expected to grasp a wide range of objects varying in shape, weight
or material type. Providing robots with tactile capabilities similar to humans
is thus essential for applications involving human-to-robot or robot-to-robot
interactions, particularly in those situations where a robot is expected to
grasp and manipulate complex objects not previously encountered. A critical
aspect for successful object grasp and manipulation is the use of high-quality
fingertips equipped with multiple high-performance sensors, distributed
appropriately across a specific contact surface.
  In this paper, we present a detailed analysis of the use of two different
types of commercially available robotic fingertips (BioTac and WTS-FT), each of
which is equipped with multiple sensors distributed across the fingertips'
contact surface. We further demonstrate that, due to the high performance of
the fingertips, a complex adaptive grasping algorithm is not required for
grasping of everyday objects. We conclude that a simple algorithm based on a
proportional controller will suffice for many grasping applications, provided
the relevant fingertips exhibit high sensitivity. In a quantified assessment,
we also demonstrate that, due in part to the sensor distribution, the
BioTac-based fingertip performs better than the WTS-FT device, in enabling
lifting of loads up to 850g, and that the simple proportional controller can
adapt the grasp even when the object is exposed to significant external
vibrational challenges.
