Jonathan Hiller and Hod Lipson
Digital materials are composed of many discrete voxels placed in a massively parallel layer deposition process, as opposed to continuous (analog) deposition techniques. The…
Abstract
Purpose
Digital materials are composed of many discrete voxels placed in a massively parallel layer deposition process, as opposed to continuous (analog) deposition techniques. The purpose of this paper is to explore the wide range of material properties attainable using a voxel‐based freeform fabrication process, and demonstrate in simulation the versatility of fabricating with multiple materials in this manner.
Design/methodology/approach
A representative interlocking voxel geometry was selected, and a nonlinear physics simulator was implemented to perform virtual tensile tests on blocks of assembled voxels of varying materials. Surface contact between tiles, plastic deformation of the individual voxels, and varying manufacturing precision were all modeled.
Findings
By varying the precision, geometry, and material of the individual voxels, continuous control over the density, elastic modulus, coefficient of thermal expansion, ductility, and failure mode of the material is obtained. Also, the effects of several hierarchical voxel “microstructures” are demonstrated, resulting in interesting properties such as negative Poisson's ratio.
Research limitations/implications
This analysis is a case study of a specific voxel geometry, which is representative of 2.5D interlocking shapes but not necessarily all types of interlocking voxels.
Practical implications
The results imply that digital materials can exhibit widely varying and tunable properties in a single desktop fabrication process.
Originality/value
The paper explores the vast potential of tunable materials, especially using the concept of voxel microstructure, applicable primarily to 3D voxel printers but also to other multi‐material freeform fabrication processes.
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Handler's genealogy of postmodernism recounted in his address recognizes its origin in aesthetic disciplines and its somewhat viral transcription into social jurisprudence: “the…
Abstract
Handler's genealogy of postmodernism recounted in his address recognizes its origin in aesthetic disciplines and its somewhat viral transcription into social jurisprudence: “the postmodern concept of subversion developed first in language and literary theory, art, and architecture and then spread into politics and law” (1992a, p. 698). Although Handler's rejection of deconstruction stems from what he sees to be its political quiescence, its association with aesthetic critiques of modernism haunts his claims as one source of its essential conservatism. Aesthetic values, he implies, remain distant or distinct from pressing issues of political and social inequality.
The progressive limits to rights mobilization have become starkly apparent in the past two decades. No new suspect classes have been forthcoming from the Supreme Court since 1977…
Abstract
The progressive limits to rights mobilization have become starkly apparent in the past two decades. No new suspect classes have been forthcoming from the Supreme Court since 1977 despite continued demands for legal recognition by lesbians and gays, indigenous peoples and others interested in expanding civil rights doctrine. Public tolerance for civil rights measures has likewise dried up. Since the 1960s, referenda on civil rights have halted affirmative action programs, limited school busing and housing discrimination protections, promoted English-only laws, limited AIDS policies, and ended the judicial recognition of same-sex marriage, among other issues. Nearly 80% of these referenda have had outcomes realizing the Madisonian fear of “majority tyranny”1 and signaling the Nietzschean dread of a politics of resentment (Brown, 1995, p. 214; Connolly, 1991, p. 64).
Jonathan Hiller and Hod Lipson
Virtual voxels (3D pixels) have traditionally been used as a graphical data structure for representing 3D geometry. The purpose of this paper is to study the use of pre‐existing…
Abstract
Purpose
Virtual voxels (3D pixels) have traditionally been used as a graphical data structure for representing 3D geometry. The purpose of this paper is to study the use of pre‐existing physical voxels as a material building‐block for layered manufacturing and present the theoretical underpinnings for a fundamentally new massively parallel additive fabrication process in which 3D matter is digital. The paper also seeks to explore the unique possibilities enabled by this paradigm.
Design/methodology/approach
Digital RP is a process whereby a physical 3D object is made of many digital units (voxels) arranged selectively in a 3D lattice, as opposed to analog (continuous) material commonly used in conventional rapid prototyping. The paper draws from fundamentals of 3D space‐filling shapes, large‐scale numerical simulation, and a survey of modern technology to reach conclusions on the feasibility of a fabricator for digital matter.
Findings
Design criteria and appropriate 3D voxel geometries are presented that self‐align and are suitable for rapid parallel assembly and economical manufacturing. Theory and numerical simulation predict dimensional accuracy to scale favorably as the number of voxels increases. Current technology will enable rapid parallel assembly of billions of microscale voxels.
Research limitations/implications
Many novel voxel functions could be realized in the electromechanical and microfluidic domains, enabling inexpensive prototyping of complex 3D integrated systems. The paper demonstrates the feasibility of a 3D digital fabricator, but an instantiation is out of scope and left to future work.
Practical implications
Digital manufacturing offers the possibility of desktop fabrication of perfectly repeatable, precise, multi‐material objects with microscale accuracy.
Originality/value
The paper constitutes a comprehensive review of physical voxel‐based manufacturing and presents the groundwork for an emerging new field of additive manufacturing.
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In this chapter, I suggest that Connecticut’s and other states’ recent discontinuation of civil unions in the name of marriage “equality” marginalizes and demeans marriage �…
Abstract
In this chapter, I suggest that Connecticut’s and other states’ recent discontinuation of civil unions in the name of marriage “equality” marginalizes and demeans marriage – rejecting people who may nonetheless wish to codify their intimate partnerships – for purposes of legal “incidents,” including rights and privileges, like hospital visitation rights, testimonial privilege, inheritance rights, etc. In doing so, I also call for a rejuvenation of the practice of granting civil union licenses in these states.