Flexible Force Sensors In article 2202142, Terry Tao Ye, Zhaoli Gao, Jian Yang, and co-workers present the layout of skin-adhesive force sensor based on piezoelectric poly(l-Lactic acid) its potential applications in human behavior recognition, such as finger, wrist, laryngeal knot movement. The is composed photocurable acrylate films, gold electrodes film with a sandwiched structure, transpare...

We investigated stability of action by a multifinger system with three methods: analysis of intertrial variance, application of transient perturbations, and analysis of the system's motion in different state spaces. The "inverse piano" device was used to apply transient (lifting-and-lowering) perturbations to individual fingers during single- and two-finger accurate force production tasks. In e...

We consider the problem of impedance control for the physical interaction between the soft tip of a robot finger, where the nonlinear characteristics of the reproducing force and the finger dynamic parameters are unknown, and a rigid object or environment under kinematic uncertainties arising from both uncertain contact point location and uncertain rigid object geometry. An adaptive controller ...

The current study evaluated subjects’ ability to control finger force during contact with a smooth plate. They were instructed to maintain a constant “light” or “medium” force when statically contacting the surface or when moving the end effector (finger or rigid probe) back and forth at 20 or 222 mm/s. Subjects pressed harder when using the probe (cf. finger) and during static contact (cf. bot...

We studied how the central nervous system (CNS) organizes outputs of effectors in a redundant motor task. During four-finger ramp force production, finger forces show positive covariations across trials at low forces, which turn into negative covariations at a critical force value (F(CR)). Subjects performed such tasks with different target amplitudes and durations of the ramp. F(CR) showed sig...

We consider problems of motor redundancy associated with handwriting using the framework of the uncontrolled manifold (UCM) hypothesis. Recent studies of finger coordination during force production tasks have demonstrated that the UCM-hypothesis provides a fruitful framework for analysis of multi-finger actions. In particular, it has been shown that during relatively fast force changes, finger ...

1. Non-invasive recording techniques of the arterial pressure pulse will distort the arterial wall and may alter pulse wave measurements. We hypothesized that intersubject variability of these measurements would be reduced if recording forces were normalized to reflect individualized arterial occlusion forces. 2. In 10 normal male subjects (age 24 +/- 1 years), brachial, radial and finger arter...

When multiple fingertips experience force sensations, how does the brain interpret the combined sensation? In particular, under what conditions are the sensations perceived as separate or, alternatively, as an integrated whole? In this work, we used a custom force-feedback device to display force signals to two fingertips (index finger and thumb) as they traveled along collinear paths. Each fin...