news & views increased. This suggests that the observed could also be an issue. All these points Ilia Valov is at the Research Centre Jülich, Electronic memory effect is a result of an interplay need to be considered and resolved to meet Materials (PGI-7), Wilhelm-Johnen- Straße, 52425 between redox reactions of the ligand and the the demands of the memory industry. In Jülich, Germany. Michael N. Kozicki is at the School of displacement of the counterions. considering where this new memristor Electrical, Computer and Energy Engineering, Arizona Despite the simplicity of the device technology might fit into emergent State University, Tempe, Arizona 85287-5706, USA. formation demonstrated in this work, applications, perhaps the most obvious being e-mail: [email protected]; [email protected] the technology proposed by Goswami neuromorphic computing, other aspects and colleagues still needs to meet the of device operation need to be examined, References 1. Chua, L. Semicond. Sci. Tech. 29, 104001 (2014). grand challenges of integration and including their analogue programmability. 2. Waser, R. & Aono, M. Nat. Mater. 6, 833–840 (2007). reliable operation in typical operating Yet the results reported in this study 3. Yang, J. J., Strukov, D. B. & Stewart, D. R. Nat. Nanotech. environments. Organic materials are prone are sufficiently compelling to drive further 8, 13–24 (2013). 4. Valov, I. & Lu, W. D. Nanoscale 8, 13828–13837 (2016). to mechanical damage and can be sensitive work. Organic materials are compatible 5. Lin, W.-P., Liu, S.-J., Gong, T., Zhao, Q. & Huang, W. Adv. Mater. to environmental conditions (moisture, with flexible circuits and can be more easily 26, 570–606 (2014). light, ionizing radiation and so on). It is also tailored for biocompatibility, potentially 6. Hino, T., Tanaka, H., Hasegawa, T., Aono, M. & Ogawa, T. Small difficult to form reliable electrodes, necessary leading to smart medical implants where 6, 1745–1748 (2010). 7. Wang, H. et al. Adv. Mater. 27, 7670–7676 (2015). for the formation of ‘real’ devices, on organic bio-electronic interfaces connect to live 8. Raeis Hosseini, N. & Lee, J.-S. ACS Nano 9, 419–426 (2015). films. In addition, organics often suffer cells. The future of this novel technology will 9. van de Burgt, Y. et al. Nat. Mater. 16, 414–418 (2017). from ageing effects that limit their lifetime. doubtless be determined by such specific 10. Goswami, S. et al. Nat. Mater. 16, 1216–1224 (2017). Operation at low and high temperatures, applications where incumbent technologies which is expected for commercial devices, are unable to perform well. ❐ Published online: 23 October 2017 MATERIAL WITNESS WHO MADE THE FIRST GLASS? No other material continually exceeds another reconsideration of the origins itself as silica glass does. Whether it is of glassmaking, indicating that there is in the stained glass of Gothic churches, after all no compelling reason to prefer the airy Crystal Palace of the Victorians this region over Egypt2. or the modern skyscrapers that mirror Shortland et al. have conducted the sky they reach towards, glass has scanning electron microscope- been constantly refined to redefine its wavelength dispersive spectroscopy architectural possibilities. Meanwhile, (SEM-WDS) analysis to deduce the in fibre composites and optical cables elemental compositions of the samples it challenges preconceptions about its (which include raw glass ingots, beads PHILIP BALL properties and limits. and fragments of worked objects), So who could not wonder when along with measurements of strontium copies of older documents, while no this substance first entered the palette and neodymium isotope ratios that Egyptian records from this period have of human-made materials? It starts to help to distinguish different sources been found. But that doesn’t mean appear in archaeological remains in of the parent silica. The results reveal Egyptians weren’t making the material. significant quantities in the Late Bronze that some of the artefacts are modern: The only real reason still to prefer Age, around 1500 bc, and consensus has introduced, presumably, by local Nuzi over Egypt, then, would be if long located the geographical origins workers during the excavation because the former technology looked more in the Middle East. But that still leaves they were paid to hand over their finds. sophisticated than the latter. But the options open. Ancient Egypt used to Most of the genuine Nuzi glass is tinted results of Shortland et al. seem to offer be the obvious and default assumption, blue by traces of copper; in contrast, no evidence of that. The Egyptian but Mesopotamia — the region mostly Egyptian glass from this period shows artefacts seem to be of higher quality, overlapping with present-day Iraq, a wider range of colorants, suggesting a and moreover have a wider colour with a distinct culture — has been a more mature glassmaking technology. range. That too doesn’t clinch the contender too for at least a century. The latest dating of the strata matter, but it leaves open the question Opinion in recent decades has at Nuzi where most of the glass of where humankind first mastered this shifted in that direction, thanks was found3 puts it pretty much most useful and beautiful of materials. especially to the finding of extensive contemporaneous with extensive glass glass remains in the city of Nuzi, near remains in Egypt, in the middle of the References Kirkuk in northern Iraq, which was second millennium bc — undermining 1. Shortland, A., Eremin, K., Kirk, S. & Armstrong, J. in Materials Issues in Art and Archaeology VIII excavated in the 1920s and 1930s. The some of the rationale for thinking (eds Vandiver, P. B., McCarthy, B., Tykot, R. H., material culture of Nuzi is currently the Nuzi glassmaking industry Ruvalcaba-Sil, J. L. & Casadio, F.) 217–232 (MRS, 2008). being re-examined in an international came first. True, there are also texts 2. Shortland, A. J., Kirk, S., Eremin, K., Degryse, P. & 1 Walton, M. Archaeometry https://doi.org/10.1111/ project . A new study of the Nuzi on glassmaking from Nineveh, the arcm.12332 (2017). glass artefacts housed at the Harvard Assyrian capital in Mesopotamia, from 3. Stein, D. L. Z. Assyriologie und Vorderasiatische Semitic Museum now argues for the first millennium, which may be Archäologie 79, 36–60 (1989).

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