CMOS Terahertz Metamaterial Based 64 × 64 Bolometric Detector Arrays

We present two terahertz detectors composed of microbolometer sensors (vanadium oxide and silicon pn diode) and metamaterial absorbers monolithically integrated into a complementary metal oxide semiconductor (CMOS) process. The metamaterial absorbers were created using the metal-dielectric-metal layers of a commercial CMOS technology resulting in low-cost terahertz detectors. The scalability of this technology was used to form a 64 × 64 pixel terahertz focal plane array

Octave-spanning broadband absorption of terahertz light using metasurface fractal-cross absorbers

Synthetic fractals inherently carry spatially encoded frequency information that renders them as an ideal candidate for broadband optical structures. Nowhere is this more true than in the terahertz (THz) band where there is a lack of naturally occurring materials with valuable optical properties. One example are perfect absorbers that are a direct step toward the development of highly sought after detectors and sensing devices. Metasurface absorbers that can be used to substitute for natural materials suffer from poor broadband performance, while those with high absorption and broadband capability typically involve complex fabrication and design and are multilayered. Here, we demonstrate a polarization-insensitive ultrathin (∼λ/6) planar metasurface THz absorber composed of supercells of fractal crosses capable of spanning one optical octave in bandwidth, while still being highly efficient. A sufficiently thick polyimide interlayer produces a unique absorption mechanism based on Salisbury screen and antireflection responses, which lends to the broadband operation. Experimental peak absorption exceeds 93%, while the average absorption is 83% from 2.82 THz to 5.15 THz. This new ultrathin device architecture, achieving an absorption-bandwidth of one optical octave, demonstrates a major advance toward a synthetic metasurface blackbody absorber in the THz ban

Improving Coping Research: Raze the Slum before Any More Building!

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67019/2/10.1177_135910539700200203.pd

Wide-Range Optical CMOS-Based Diagnostics

Colorimetric, chemiluminescence and refractive index based diagnostics are some of the most important sensing techniques in biomedical science and clinical medicine. Conventionally laboratories and medical clinics rely on bulky and dedicated equipment for each diagnostic technique independently. In this paper, we present CMOS sensor based solutions, comprising a single photon avalanche detector array and photodiode array. The CMOS platform offers low cost integration and wide range of light-based diagnostic techniques, leading to development of point-of-care devices

Larger lacertid lizard species produce higher than expected iliotibialis muscle power output; the evolution of muscle contractile mechanics with body size in lacertid lizards

Increases in body size can lead to alterations in morphology, physiology, locomotor performance and behaviour of animals. Most studies considering the effects of scaling on muscle performance have studied within-species effects, with few studies considering differences between species. A previous review of published data indicates that maximum muscle-shortening velocity decreases, but that maximum isometric stress does not change, with increased body mass across species of terrestrial animals. However, such previous analyses do not account for the phylogenetic relatedness of the species studied. Our aim was to use phylogenetically informed analysis to determine the effects of body size on isolated iliotibialis muscle performance across 17 species of lacertid lizards. Between one and five individuals were used to obtain mean performance values for each species. We analysed the relationship between each variable and body size, as estimated by snout-vent length (SVL), whilst taking into account the phylogenetic relationships between species. We found that isometric tetanus relaxation time, maximal tetanus stress (force per muscle cross-sectional area) and maximal work loop power output (normalised to muscle mass) all significantly increased with greater SVL. In contrast, fatigue resistance during repeated work loops significantly decreased with SVL and there was no effect of size on tetanus activation time. When we compare our findings with those that would be predicted by dynamic similarity, then as these lacertid species become bigger, there is a greater than expected increase in the normalised muscle power output, probably to counter the larger than expected increase in body mass

A 16 x 16 CMOS amperometric microelectrode array for simultaneous electrochemical measurements

There is a requirement for an electrochemical sensor technology capable of making multivariate measurements in environmental, healthcare, and manufacturing applications. Here, we present a new device that is highly parallelized with an excellent bandwidth. For the first time, electrochemical cross-talk for a chip-based sensor is defined and characterized. The new CMOS electrochemical sensor chip is capable of simultaneously taking multiple, independent electroanalytical measurements. The chip is structured as an electrochemical cell microarray, comprised of a microelectrode array connected to embedded self-contained potentiostats. Speed and sensitivity are essential in dynamic variable electrochemical systems. Owing to the parallel function of the system, rapid data collection is possible while maintaining an appropriately low-scan rate. By performing multiple, simultaneous cyclic voltammetry scans in each of the electrochemical cells on the chip surface, we are able to show (with a cell-to-cell pitch of 456 μm) that the signal cross-talk is only 12% between nearest neighbors in a ferrocene rich solution. The system opens up the possibility to use multiple independently controlled electrochemical sensors on a single chip for applications in DNA sensing, medical diagnostics, environmental sensing, the food industry, neuronal sensing, and drug discovery

Exploitation of magnetic dipole resonances in metal–insulator–metal plasmonic nanostructures to selectively filter visible light

Significant improvement in using plasmonic nanostructures for practical color filtering and multispectral imaging applications is achieved by exploiting the coupling of surface plasmons with dielectric optical cavity resonances within a hexagonal array of subwavelength holes in a thin CMOS-compatible metal–insulator–metal stack. This polarization-independent architecture overcomes the limitations of all previously reported plasmonic color filters, namely poor transmission and broad band-pass characteristic, effectively providing a compact approach for high color accuracy multispectral and filtering technologies. Measured transmission efficiencies up to 60% and full-width at half-maximum between 45 and 55 nm along the entire visible spectrum are achieved, an impressive and unique combination of features that has never been reported before. The nanostructure exploits the phenomenon of extraordinary optical transmission and magnetic dipole modes to efficiently filter visible light. The presence of magnetic resonances in the optical regime is an unusual property, previously reported in photonic metamaterials or dielectric nanoparticles. The physical insights established from the electromagnetic near-field patterns are used to accurately tailor the optical properties of the filters. The nonideality of the fabrication at the nanoscale is addressed, the issues encountered highlighted, and alternative solutions proposed and verified, demonstrating that the working principle of the MIM structure can be successfully extended to other materials and structural parameters

A hermeneutics of the ontology of time and technology

There is a double meaning in the name of this thesis. This duality emerges from how the term ‘hermeneutics’ can be applied. In one sense the hermeneutics of this thesis is a textual interpretation of the philosophical history of ontology. This is an interpretation of ontological theory from its genesis with the Pre-Socratic concern with the ‘question of being’ and onwards through its salient historical developments up until the early twentieth century. The thesis interprets these developments as nevertheless maintaining a foundational understanding of ‘being’ as ‘quiddity’ or ‘what-ness’. While the ontological tradition diverges over disagreements about ‘realism’, ‘idealism’, or ‘nominalism’, for example, these disagreements are interpreted as having an unchanging understanding of ‘being’ in terms of ‘what-ness’ that unites them. Furthermore, this traditional understanding of ‘being’ as ‘what-ness’ is documented as having an implicit connection to a conceptual model of human understanding that divides the knowing subject from the known object. In opposition to a prominent interpretation that identifies this model as a Cartesian development, it is rather presented that it has roots that can be found within the philosophy of Plato. Moreover, this model is interpreted as being contingent on the technological development and adoption of literacy that predicated an emergent and reflexive understanding of the ‘what-ness’ of the self-subject. However, this textual hermeneutics of the history of ontology also presents the challenge to understanding ‘being’ as ‘what-ness’ that occurred in the early twentieth century. This is found in the philosophy of Martin Heidegger, and in particular in his treatise Being and Time. This alternative understanding of ‘being’ is interpreted as presenting an ontology of ‘how-ness’. This understanding of ‘being’ as ‘how-ness’, as opposed to ‘what-ness’, is presented through Heidegger’s introduction of the concept of the ‘ontological difference’. This concept, it is shown, enables Heidegger’s understanding of human existentiality as self-interpretation. In addition, the inheritance of this ontological thesis of self-interpretative existence is traced from its phenomenological, hermeneutic, and existentialist roots. This includes the analysis of the ideas of such scholars as Friedrich Schleiermacher, Wilhelm Dilthey, and Edmund Husserl. Through documenting this provenance, the duality of this thesis’ title is demonstrated. It is not only a textual hermeneutics that is presented in this treatise, but also an example of hermeneutic phenomenology. Hermeneutic phenomenology, as Heidegger argued, is presented as the methodology for an ontology that understands human existentiality as self-interpretative. This methodology is analysed, and differing interpretations of its processes are critiqued. Furthermore, by interpreting human existentiality as hermeneutic, Heidegger’s understanding of ‘being’ as temporal is elucidated. The thesis of the temporality of human existentiality is then explained in terms of its structure as ‘being-in-the-world’. The equiprimordial characteristics of ‘being-in-the-world’ are analysed, such as ‘who-ness’, ‘there-ness’, and ‘world-ness’, and these are shown to together constitute human existentiality. The thesis then concludes by demonstrating how this hermeneutic phenomenology of ontological ‘how-ness’ also enables the explication of the temporality of technological existentiality