The contribution of air to ultrasonic friction reduction

Friesen, Rebecca Fenton; Wiertlewski, Michaël; Peshkin, Michael A.; Colgate, J. Edward

doi:10.1109/whc.2017.7989955

Cited by 7 publications

(4 citation statements)

References 13 publications

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“…There are two primary strategies to actively modulate the friction forces felt on a surface: ultrasonic vibration and electroadhesion. Ultrasonic vibrations lower the friction between skin and a surface through a combination of reducing the total contact area and increasing the lubricating effect of air at the interface. − Electroadhesion raises the friction felt using the capacitive force between skin and the surface to draw the skin toward the interface and increase the surface area. , Although both are generally compatible with existing smart screen technologies, several engineering challenges in ultrasonic vibration schemessuch as mechanically moving parts, the inability to implement multi-finger haptics, relatively high power consumption, and limited variability in the friction coefficienthave motivated researchers to explore and improve electroadhesion devices.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Electrowetting Effect on the Interfacial Mechanics between Human Corneocytes and Nanoasperities

Boonpuek

Choi

et al. 2021

Langmuir

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A large subset of haptic surfaces employs electroadhesion to modulate both adhesion and friction at a sliding finger interface. The current theory of electroadhesion assumes that the applied electric field pulls the skin into stronger contact, increasing friction by increasing the real contact area, yet it is unknown what role environmental moisture plays in the effect. This paper uses atomic force microscopy (AFM)to determine the effect of humidity on the adhesion and friction between the single nanoscale asperity and individual human finger corneocytes. An analytical model of the total effective load of the AFM tip is developed to explain the humidity−voltage dependence of nanoscale adhesion and friction at contacting asperities. The results show that the electrowetting effect at the interface at high humidity accounts for 35% of the adhesive force but less than 8% of the total friction, implying that the electrowetting effect can be enhanced by optimizing surface topography to promote the formation and rupture of liquid menisci.

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Section: Introductionmentioning

confidence: 99%

Evaluation of the Electrowetting Effect on the Interfacial Mechanics between Human Corneocytes and Nanoasperities

Boonpuek

Choi

et al. 2021

Langmuir

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“…This overpressure causes the two objects to separate, as shown in Fig. 1(b), resulting in a controllable coefficient of friction-a phenomenon known as ultrasonic friction modulation or ultrasonic lubrication [9], [10]. The amount of separation is monotonically correlated to the vibration amplitude, enabling precise and controllable active lubrication at the interface [9].…”

Section: Working Principle and Design Ultrasonic Lubricationmentioning

confidence: 99%

Toward

Atalla,

Tuijp,

Wiertlewski

et al. 2024

Preprint

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Minimally invasive endovascular procedures uses catheters that are guided through blood vessels to perform interventions, resulting in an inevitable frictional interaction between the catheter and the vessel walls. While this friction enhances stability during the intervention, it poses a risk of damaging the inner layer of the blood vessel wall during navigation, leading to post-operative complications including infectious diseases and thrombus formation. To mitigate the risk of adverse complications, we propose a new concept of a variable friction catheter capable of transitioning from low friction during navigation to high friction for increased stability while performing the intervention. This variable friction catheter leverages ultrasonic lubrication to actively control the frictional forces experienced by the catheter during the procedure. In this paper, we present a proof-of-concept for a friction control module, a pivotal component of the proposed catheter design. Our experiments demonstrate that the prototype effectively reduce friction by up to 60% and 11% in average on rigid and soft surfaces respectively, underscoring the feasibility of the design and its potential to improve the safety and efficacy of minimally invasive endovascular procedures.

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“…An alternative to squeeze-film theory argues that the skin bounces on the plate, making intermittent contact of short duration, resulting in a reduction in the overall friction [20], [21]. Recent investigations under reduced pressure showed that air is nonetheless a critical factor in the modulation of friction [16], [22].…”

Section: Ultrasonic Friction Reduction Theoriesmentioning

confidence: 99%

“…In addition to levitation, the skin is forced into oscillation by the plate. During each oscillation, the gap closes, creating a cushion of air on which the tissues bounce [16]. Kaci et al derived a method to estimate the acoustic force applied to the skin during the harmonic oscillation produced by piezoelectric actuators.…”

Section: Introductionmentioning

confidence: 99%

Estimating Friction Modulation From the Ultrasonic Mechanical Impedance

Huloux

Bernard

Wiertlewski

2021

IEEE Trans. Haptics

Self Cite

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Ultrasonic surface-haptic touchscreens produce compelling tactile sensations directly on the users' fingertips. The tactile sensations stem from the modulation of friction produced by acoustic radiation pressure, which reduces the contact between the skin and the glass plate. During this process, some of the vibrations are partly absorbed by the tissues, resulting in a conspicuous change in the vibration amplitude of the plate upon contact with the finger, which manifests as a net change in the system mechanical impedance. In this study, we leverage the observable change of impedance to estimate the acoustic levitation and the frictional force. The self-sensing method utilizes a model of the first principles governing the physical interaction between the plate and the skin, which relies on multi-scale contact theory. The model accurately describes the experimental influence of the amplitude on the observed impedance (i.e., the amount of energy absorbed and reflected) and can be used to estimate the friction coefficient (R 2 = 0.93). These results provide additional evidence of the partial levitation mechanism at play in ultrasonic friction-modulation. This finding can be useful for designing energy-efficient devices and provide design suggestions for using ultrasonic impedance for self-sensing friction forces.

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The contribution of air to ultrasonic friction reduction

Cited by 7 publications

References 13 publications

Evaluation of the Electrowetting Effect on the Interfacial Mechanics between Human Corneocytes and Nanoasperities

Evaluation of the Electrowetting Effect on the Interfacial Mechanics between Human Corneocytes and Nanoasperities

Toward

Estimating Friction Modulation From the Ultrasonic Mechanical Impedance

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