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Emerging wearable devices are very attractive and promising in biomedical and healthcare fields because of their biocompatibility for monitoring in situ biomarker-associated signals and external stimulus. Many such devices or systems demand microscale sensors fabricated on curved and flexible hydrogel substrates. However, fabrication of microstructures on such substrates is still challenging because the traditional planar lithography process is not compatible with curved, flexible, and hydrated substrates. Here, we present a shadow-mask-assisted deposition process capable of directly generating metallic microstructures on the curved hydrogel substrate, specifically the contact lens, one of the most popular hydrogel substrates for wearable biomedical applications. In this process, the curved hydrogel substrate is temporarily flattened on a planar surface and metal features are deposited on this substrate through a shadow mask. To achieve a high patterning fidelity, we have experimentally and theoretically investigated various types of distortion due to wrinkles on 3D-printed sample holders, geometric distortion of the substrate due to the flattening process, and volume change of the hydrogel material during the dehydration and hydration processes of the contact lens. Using this method, we have demonstrated fabrication of various titanium pattern arrays on contact lenses with high fidelity and yield.
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Geometric Trajectory Planning for Robot Motion Over a 3D Surface
Mapping a desired 2D pattern onto a curved surface has many applications. This includes motion planning for mobile robots to perform coverage path planing, robot end effector trajectory design for tasks such as printing, depositing, wielding on a 3D surface. This problem becomes more difficult if we want the mapped pattern to keep the properties of the original pattern (i.e, least possible mapping distortion), and pass over some desired points and/or remain bounded in a specific region on the surface. In this paper, we apply surface parameterization and mapping distortion analysis, which is rarely used in robot motion planning works, to map a pattern onto 3D surface. To meet additional goals such as passing over certain points, a planar mapping determined by constrained optimization is employed on the original pattern. Our focus is on printing/depositing materials on curved surfaces, and simulations and experiments are provided to confirm the performance of the approach.
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- Award ID(s):
- 1563424
- PAR ID:
- 10161917
- Date Published:
- Journal Name:
- ASME 2019 Dynamic Systems and Control Conference
- Volume:
- 3
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1115/DSCC2019-9063
