EigenNail for Finger Force Direction Recognition

Biomechanical studies of the elongated canine tooth of animals are few, and thus our understanding of mechanical and physical properties of animal teeth is limited. The objective of the present study was to evaluate the influence of force direction on fracture resistance and fracture pattern of canine teeth in an ex vivo dog cadaver model. Forty-five extracted canine teeth from laboratory beagle dogs were standardized by hard tissue volume and randomly distributed among 3 force direction groups. The teeth were secured within a universal testing machine and a load was applied at different directions based on testing group. The maximum force to fracture and the fracture pattern classification were recorded for each tooth. After correcting for hard tissue cross-sectional area in a multivariate analysis, no significant difference in the amount of force required for fracture was apparent between the different force direction groups. However, the influence of force direction on fracture pattern was significant. The results of this study may allow the clinician to educate clients on possible causal force directions in clinically fractured teeth and, thus, help prevent any contributing behavior in the future.

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Aging differentially affects online control and offline control in finger force production

PLoS ONE ◽

10.1371/journal.pone.0198084 ◽

2018 ◽

Vol 13 (5) ◽

pp. e0198084

Author(s):

Yang Sun Park ◽

Kyung Koh ◽

Hyun Joon Kwon ◽

Okjin Lee ◽

Jae Kun Shim

Keyword(s):

Force Production ◽

Online Control ◽

Finger Force

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Plasmonic linear nanomotor using lateral optical forces

Science Advances ◽

10.1126/sciadv.abc3726 ◽

2020 ◽

Vol 6 (45) ◽

pp. eabc3726

Author(s):

Yoshito Y. Tanaka ◽

Pablo Albella ◽

Mohsen Rahmani ◽

Vincenzo Giannini ◽

Stefan A. Maier ◽

...

Keyword(s):

Laser Beam ◽

Incident Light ◽

Lateral Force ◽

Diffraction Limit ◽

Propagation Direction ◽

Optical Force ◽

Optical Forces ◽

Incident Laser ◽

New Class ◽

Force Direction

Optical force is a powerful tool to actuate micromachines. Conventional approaches often require focusing and steering an incident laser beam, resulting in a bottleneck for the integration of the optically actuated machines. Here, we propose a linear nanomotor based on a plasmonic particle that generates, even when illuminated with a plane wave, a lateral optical force due to its directional side scattering. This force direction is determined by the orientation of the nanoparticle rather than a field gradient or propagation direction of the incident light. We demonstrate the arrangements of the particles allow controlling the lateral force distributions with the resolution beyond the diffraction limit, which can produce movements, as designed, of microobjects in which they are embedded without shaping and steering the laser beam. Our nanomotor to engineer the experienced force can open the door to a new class of micro/nanomechanical devices that can be entirely operated by light.

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Tactile Interaction Sensor with Millimeter Sensing Acuity

Sensors ◽

10.3390/s21134274 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4274

Author(s):

Eunsuk Choi ◽

Sunjin Kim ◽

Jinsil Gong ◽

Hyeonjeong Sun ◽

Minjin Kwon ◽

...

Keyword(s):

Shear Force ◽

High Reliability ◽

Normal Pressure ◽

Low Noise ◽

Sensing Material ◽

High Uniformity ◽

Tactile Interaction ◽

Force Direction ◽

Potential Applications ◽

Contact Shape

In this article we report on a 3 × 3 mm tactile interaction sensor that is able to simultaneously detect pressure level, pressure distribution, and shear force direction. The sensor consists of multiple mechanical switches under a conducting diaphragm. An external stimulus is measured by the deflection of the diaphragm and the arrangement of mechanical switches, resulting in low noise, high reliability, and high uniformity. Our sensor is able to detect tactile forces as small as ~50 mgf along with the direction of the shear force. It also distinguishes whether there is a normal pressure during slip motion. We also succeed in detecting the contact shape and the contact motion, demonstrating potential applications in robotics and remote input interfaces. Since our sensor has a simple structure and its function depends only on sensor dimensions, not on an active sensing material, in comparison with previous tactile sensors, our sensor shows high uniformity and reliability for an array-type integration.

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