title: Interfacial pressure and shear sensor system for fingertip contact applications.
abstract: This Letter presents a capacitive-based sensor system for fingertip contact applications. It is capable of simultaneously measuring normal (pressure) and tangential (shear) stresses at the interface between a fingertip and external objects. This could be potentially exploitable for applications in the fields of upper limb prosthetics, robotics, hand rehabilitation and so on. The system was calibrated and its performance was tested using a test machine. To do so, specific test protocols reproducing typical stress profiles in fingertip contact interactions were designed. Results show the system's capability to measure the applied pressure and stresses, respectively, with high linearity between the measured and applied stresses. Subsequently, as a case study, a 'press-drag-lift' based fingertip contact test was conducted by using a finger of a healthy subject. This was to provide an initial evaluation for real-life applications. The case study results indicate that both interface pressure and shear were indeed measured simultaneously, which aligns well with the designed finger test protocols. The potential applications for the sensor system and corresponding future works are also discussed.
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: Maria
authors.initials: M
authors.lastname: Valero
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Hale
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: Liudi
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: Mike
authors.initials: M
authors.lastname: McGrath
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: Jianliang
authors.initials: J
authors.lastname: Gao
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: Piotr
authors.initials: P
authors.lastname: Laszczak
authors.affiliation: Engineering Sciences, Faculty of Engineering and the Environment , University of Southampton , Southampton SO17 1BJ , UK.
authors.forename: David
authors.initials: D
authors.lastname: Moser
keywords: capacitive based sensor system; capacitive sensors; fingertip contact applications; hand rehabilitation; interfacial pressure; pressure sensors; prosthetics; robotics; shear sensor system; tangential stresses; upper limb prosthetics