When the human fingertip is pressed against a surface or bent, the hemodynamic state of the fingertip is altered due to mechanical interactions between the fingernail and bone. Normal force, shear force, and finger extension/flexion all result in different patterns of blood volume beneath the fingernail. This phenomenon has been exploited in order to detect finger forces and finger posture by c...

The present study aimed to elucidate whether the type of feedback influences the performance and the motor cortical activity when executing identical visuomotor tasks. For this purpose, time to task failure was measured during position- and force-controlled muscular contractions. Subjects received either visual feedback about the force produced by pressing a force transducer or about the actual...

Parallel pinch is an important grasp method. The end phalanx of the traditional parallel and self-adaptive gripper moves in arc trajectory, which requires auxiliary lifting motion industrial manipulator, inconvenient to use. To solve this problem, a novel robot finger designed implemented—Hoecken’s finger. In finger, Hoecken linkage mechanism used realize straight-line trajectory joint, differe...

This paper numerically studies two-finger grasping of deformable curve-like objects under frictional contacts. The action is like squeezing. Deformation is modeled by a degenerated version of the thin shell theory. Several differences from rigid body grasping are shown. First, under a squeeze, the friction cone at each finger contact rotates in a direction that depends on the deformable object’...

When a person produces a force with a fingertip, other fingers of the hand also show an increase in their force. This phenomenon has been termed enslaving (Li et al. 1998a; Zatsiorsky et al. 2000). When several fingers are activated simultaneously, the relations among fingers can be described with an inter-finger matrix (IMF). We suggest using the IMFs to quantify individual differences among h...

When grasping and holding an object with five digits under a variety of task constraints, subjects use well-defined force coordination patterns, i.e., consistent force covariations and in-phase synchronization among all digit pairs. The question arises as to whether these force coordination patterns are default mechanisms for controlling multi-digit force production or whether they are specific...

We present a MEMS microphone that converts the mechanical motion of a diaphragm, generated by acoustic waves, to an electrical output voltage by capacitive fingers. The sensitivity of a microphone is one of the most important properties of its design. The sensitivity is proportional to the applied bias voltage. However, it is limited by the pull-in voltage, which causes the parallel plates to c...