
Amar Hajj-Ahmad
Ph.D. Student in Mechanical Engineering, admitted Autumn 2018
All Publications
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Bimanual Handling of Deformable Objects With Hybrid Adhesion
IEEE ROBOTICS AND AUTOMATION LETTERS
2022; 7 (2): 5497-5503
View details for DOI 10.1109/LRA.2022.3158231
View details for Web of Science ID 000770589900013
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Cutting to the Point: Directly Machined Metal Molds for Directional Gecko-Inspired Adhesives
JOURNAL OF MICRO AND NANO-MANUFACTURING
2021; 9 (2)
View details for DOI 10.1115/1.4051406
View details for Web of Science ID 000698752800001
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Hybrid electrostatic and gecko-inspired gripping pads for manipulating bulky, non-smooth items
SMART MATERIALS AND STRUCTURES
2021; 30 (2)
View details for DOI 10.1088/1361-665X/abca51
View details for Web of Science ID 000600072700001
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Forcing the issue: testing gecko-inspired adhesives.
Journal of the Royal Society, Interface
2021; 18 (174): 20200730
Abstract
Materials are traditionally tested either by imposing controlled displacements and measuring the corresponding forces, or by imposing controlled forces. The first of these approaches is more common because it is straightforward to control the displacements of a stiff apparatus and, if the material suddenly fails, little energy is released. However, when testing gecko-inspired adhesives, an applied force paradigm is closer to how the adhesives are loaded in practice. Moreover, we demonstrate that the controlled displacement paradigm can lead to artefacts in the assumed behaviour unless the imposed loading trajectory precisely matches the deflections that would occur in applications. We present the design of a controlled-force system and protocol for testing directional gecko-inspired adhesives and show that results obtained with it are in some cases substantially different from those with controlled-displacement testing. An advantage of the controlled-force testing approach is that it allows accurate generation of adhesive limit curves without prior knowledge of the expected behaviour of the material or the loading details associated with practical applications.
View details for DOI 10.1098/rsif.2020.0730
View details for PubMedID 33435840