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Levine DJ, Lee OA, Campbell GM, McBride MK, Kim HJ, Turner KT, Hayward RC, Pikul JH. A Low-Voltage, High-Force Capacity Electroadhesive Clutch Based on Ionoelastomer Heterojunctions. Adv Mater 2023; 35:e2304455. [PMID: 37734086 DOI: 10.1002/adma.202304455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/18/2023] [Indexed: 09/23/2023]
Abstract
Electroadhesive devices with dielectric films can electrically program changes in stiffness and adhesion, but require hundreds of volts and are subject to failure by dielectric breakdown. Recent work on ionoelastomer heterojunctions has enabled reversible electroadhesion with low voltages, but these materials exhibit limited force capacities and high detachment forces. It is a grand challenge to engineer electroadhesives with large force capacities and programmable detachment at low voltages (<10 V). In this work, tough ionoelastomer/metal mesh composites with low surface energies are synthesized and surface roughness is controlled to realize sub-ten-volt clutches that are small, strong, and easily detachable. Models based on fracture and contact mechanics explain how clutch compliance and surface texture affect force capacity and contact area, which is validated over different geometries and voltages. These ionoelastomer clutches outperform the best existing electroadhesive clutches by fivefold in force capacity per unit area (102 N cm-2 ), with a 40-fold reduction in operating voltage (± 7.5 V). Finally, the ability of the ionoelastomer clutches to resist bending moments in a finger wearable and as a reversible adhesive in an adjustable phone mount is demonstrated.
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Affiliation(s)
- D J Levine
- Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - O A Lee
- Materials Science and Engineering, University of Colorado, Boulder, CO, 80303, USA
| | - G M Campbell
- Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - M K McBride
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80303, USA
| | - H J Kim
- Department of Chemical and Biomolecular Engineering, Sogang University, Seoul, 04107, South Korea
| | - K T Turner
- Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - R C Hayward
- Materials Science and Engineering, University of Colorado, Boulder, CO, 80303, USA
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80303, USA
| | - J H Pikul
- Department of Mechanical Engineering & Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
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Abstract
Case reports remain an important source of data in the debate over the carcinogenic effect of asbestos-containing automotive friction products. This report documents a case of pleural mesothelioma accompanied by asbestos bodies in the lung tissue of a career auto mechanic with no other known sources of exposure. Previously unreported historical and contemporary exposure data are also discussed in the context of providing additional support for the proposition that work with asbestos-containing automotive products presents a risk of significant exposure. While there remains a body of negative epidemiology that fails to find an increased risk of disease among auto workers, those data must be approached with caution. Many of those studies have drawn technical criticisms, which are beyond the scope of this report, but they remain a key part of the legal defense mounted by defendant-companies who are involved in asbestos-related litigation. This ongoing debate provides the context for the continued relevance of case reports such as this one, as well as the presentation of new and previously unpublished exposure data.
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