Electrowetting: A Consideration in Electroadhesion

Li, Xinyi; Choi, C. S.; Ma, Yuan; Boonpuek, Perawat; Felts, Jonathan R.; Mullenbach, Joe; Shultz, Craig; Colgate, J. Edward; Hipwell, M. Cynthia

doi:10.1109/toh.2020.2979439

Cited by 24 publications

(28 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[4][5][6] Compared to other mechanisms, electro-adhesion provides several advantages, such as precise control of adhesive force, fast response, lack of residue, quiet operation, and low energy consumption. [7][8][9] In particular, electro-adhesives have become increasingly adopted within the fields of haptics and robotics-for example to enable soft grippers, [10][11][12] wall climbing robots, [13][14][15] , touchscreens, [16][17][18] and haptic gloves for touching virtual objects [19,20] -thanks to their ability to function with stretchable dielectrics, small sizes, and low weights.…”

mentioning

confidence: 99%

Low‐Voltage Reversible Electroadhesion of Ionoelastomer Junctions

et al. 2020

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 99%

Low‐Voltage Reversible Electroadhesion of Ionoelastomer Junctions

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Friction forces of the four samples (uncoated, hydrophilic samples A, B and coated, hydrophobic samples A, B) were measured at 1 N normal load with the custom‐built tribometer [ 6 ] for various RH levels ( Figure b). For hydrophilic samples, the friction force of sample A is always higher than sample B and this difference becomes more significant at higher humidity above 55%, whereas the friction forces of the two coated samples are almost identical within the tested humidity range.…”

Section: Resultsmentioning

confidence: 99%

“…Environmental temperature, relative humidity (RH), skin properties, and sweating rates are believed to be the main source of variability in the performance of electroadhesion‐based surface haptic devices. [ 4,6 ] These demands require a comprehensive understanding of the underlying physics in the touch interface.…”

Section: Introductionmentioning

confidence: 99%

“…[ 9,10 ] The capillary bridges and external electric field for electroadhesion further interact with finger surface tissue and affect the real contact area. [ 6,16 ] The complexity of interactions is challenging to model properly. 2) The interfacial forces are not simply additive.…”

Section: Introductionmentioning

confidence: 99%

“…It has been demonstrated that electroadhesion modulates friction force by applying an electric field between human fingertips and screen surfaces. [ 3–6 ] This electric field changes the real contact area and thus increases friction force according to Bowden and Tabor's adhesion friction model [ 7 ]

\begin{matrix} F = τ A \end{matrix}

where τ is the interfacial shear strength of skin and A is the real contact area. Previous work has shown that friction force between the fingertip and textured surfaces is strongly influenced by electric field and capillary formation.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nanotexture Shape and Surface Energy Impact on Electroadhesive Human–Machine Interface Performance

Choi

et al. 2021

Advanced Materials

Self Cite

View full text Add to dashboard Cite

With the ubiquity of touch screens and the commercialization of electroadhesion‐based surface haptic devices, modeling tools that capture the multiphysical phenomena within the finger–device interface and their interaction are critical to design devices that achieve higher performance and reliability at lower cost. While electroadhesion has successfully demonstrated the capability to change tactile perception through friction modulation, the mechanism of electroadhesion in the finger–device interface is still unclear, partly due to the complex interfacial physics including contact deformation, capillary formation, electric field, and their complicated coupling effects that have not been addressed comprehensively. A multiphysics model is presented here to predict the friction force for finger–surface tactile interactions at the nanoscale. The nanoscopic multiphysical phenomena are coupled to study the impacts of nanotexture and surface energy in the touch interface. With macroscopic friction force measurements as verification, the model is further used to propose textures that have maximum electroadhesion effect and minimum sensitivity to relative humidity and user perspiration rate. This model can guide the performance improvement of future electroadhesion‐based surface haptic devices and other touch‐based human–machine interfaces.

show abstract

Preferential Contamination in Electroadhesive Touchscreens: Mechanisms, Multiphysics Model, and Solutions

Chatterjee,

Ma,

Sanghani

et al. 2023

Adv Materials Technologies

Self Cite

View full text Add to dashboard Cite

Electroadhesive surface haptic touchscreens can help augment user experiences by providing tactile effects. The electrode layout in current commercialized designs has separated electrodes for the sensing and actuating functions. During regular use, it is observed that fingerprint residue preferentially deposits on the actuating electrodes far more than the sensing electrodes, which makes the underlying electrode pattern apparent and is highly undesirable for touchscreen users. To address this issue, various physical phenomena (electrohydrodynamic deformation, capillary bridge stabilization, electrowetting, and electrophoretic deposition) are investigated to understand the mechanism. Through experimentation, multiphysics modeling, and surface characterization, it is found that the root cause can be attributed to two mechanisms occurring in the actuating regions: 1) electrohydrodynamic deformation of sebum droplets attached to the finger valleys leading to the formation of additional capillary bridges and residual droplets on the screen surface after their rupture, and 2) electric field‐induced stabilization of sebum capillary bridges existing between the finger ridges and the screen, leading to the coalescence and formation of larger‐sized droplets. The developed model can then be used to address the issue during the screen design process. An example of using the model to explore the impact of changes in screen oleophobicity is shown.

show abstract

Electrowetting: A Consideration in Electroadhesion

Cited by 24 publications

References 27 publications

Low‐Voltage Reversible Electroadhesion of Ionoelastomer Junctions

Low‐Voltage Reversible Electroadhesion of Ionoelastomer Junctions

Nanotexture Shape and Surface Energy Impact on Electroadhesive Human–Machine Interface Performance

Preferential Contamination in Electroadhesive Touchscreens: Mechanisms, Multiphysics Model, and Solutions

Contact Info

Product

Resources

About