Shape skeletonization （i.e., medial axis extraction） is powerful in many visual computing applications, such as pattern recognition, object segmentation, registration, and animation. In this paper, the authors expan...Shape skeletonization （i.e., medial axis extraction） is powerful in many visual computing applications, such as pattern recognition, object segmentation, registration, and animation. In this paper, the authors expand the use of diffusion equations combined with distance field information to approximate medial axes of arbitrary 3D differential properties. It offers an alternative solids represented by polygonal meshes based on their but natural way for medial axis extraction for commonly used 3D polygonal models. By solving the PDE along time axis, this system can not only quickly extract diffusion-based medial axes of input meshes, but also allow users to visualize the extraction process at each time step. In addition, the proposed model provides users a set of manipulation toolkits to sculpt extracted medial axes, then use diffusion-based techniques to recover corresponding deformed shapes according to the original input datasets. This skeleton-based shape manipulation offers a fast and easy way for animation and deformation of complicated mesh objects.展开更多
The capability to manipulate liquid shape at the microscale has enabled numerous microfluidic devices.Due to its simple electric actuation,electrowetting-on-dielectric has been widely used in a variety of microfluidic...The capability to manipulate liquid shape at the microscale has enabled numerous microfluidic devices.Due to its simple electric actuation,electrowetting-on-dielectric has been widely used in a variety of microfluidic applications that require reversible liquid-shape modulation.However,its use of dielectric and hydrophobic layers raised operation voltage,caused reliability issues,and increased fabrication cost.As an alternative mechanism,ionic-surfactant-mediated electro-dewetting has recently been demonstrated to enable digital microfluidics in air with a much lower voltage,higher reliability,and simpler chip fabrication.However,electro-dewetting for liquid-shape manipulation has remained poorly explored due to its limited contact-angle changes.Here,we investigated electro-dewetting in oil by testing various droplet liquids and hydrophilic substrate materials.To guide device development,cationic surfactants with varying hydrocarbon chain lengths and concentrations are tested.Acontact-angle change of 100◦is obtained for electro-dewetting of a dimethyl sulfoxide droplet in hexadecane with mere 4 V.To evaluate the utility of electro-dewetting in oil,proof-ofconcept devices are assembled to explore the potential in optical applications such as reflective displays and liquid lenses.Compatible with various liquids and substrates,electro-dewetting with the liquid-in-oil configuration opens a door for simpler and more reliablemicrofluidic devices.展开更多
基金This research was supported in part by the National Science Foundation (NSF) Information Technology Research under Grant No.IIS-0082035the NSF under Grant No.IIS-0097646+1 种基金Alfred P.Sloan Fellowship,Honda Initiation Awardan appointment of Haixia Du to the NLM Research Participation Program sponsored by the National Library of Medicine and administered by the Oak Ridge Institute for Science and Education
文摘Shape skeletonization （i.e., medial axis extraction） is powerful in many visual computing applications, such as pattern recognition, object segmentation, registration, and animation. In this paper, the authors expand the use of diffusion equations combined with distance field information to approximate medial axes of arbitrary 3D differential properties. It offers an alternative solids represented by polygonal meshes based on their but natural way for medial axis extraction for commonly used 3D polygonal models. By solving the PDE along time axis, this system can not only quickly extract diffusion-based medial axes of input meshes, but also allow users to visualize the extraction process at each time step. In addition, the proposed model provides users a set of manipulation toolkits to sculpt extracted medial axes, then use diffusion-based techniques to recover corresponding deformed shapes according to the original input datasets. This skeleton-based shape manipulation offers a fast and easy way for animation and deformation of complicated mesh objects.
文摘The capability to manipulate liquid shape at the microscale has enabled numerous microfluidic devices.Due to its simple electric actuation,electrowetting-on-dielectric has been widely used in a variety of microfluidic applications that require reversible liquid-shape modulation.However,its use of dielectric and hydrophobic layers raised operation voltage,caused reliability issues,and increased fabrication cost.As an alternative mechanism,ionic-surfactant-mediated electro-dewetting has recently been demonstrated to enable digital microfluidics in air with a much lower voltage,higher reliability,and simpler chip fabrication.However,electro-dewetting for liquid-shape manipulation has remained poorly explored due to its limited contact-angle changes.Here,we investigated electro-dewetting in oil by testing various droplet liquids and hydrophilic substrate materials.To guide device development,cationic surfactants with varying hydrocarbon chain lengths and concentrations are tested.Acontact-angle change of 100◦is obtained for electro-dewetting of a dimethyl sulfoxide droplet in hexadecane with mere 4 V.To evaluate the utility of electro-dewetting in oil,proof-ofconcept devices are assembled to explore the potential in optical applications such as reflective displays and liquid lenses.Compatible with various liquids and substrates,electro-dewetting with the liquid-in-oil configuration opens a door for simpler and more reliablemicrofluidic devices.
