Oversea speaker

December 13 2023 (Wednesday) 3:30-4:30pm
Although recent research efforts in material development, device designs, and fabrication strategies have resulted in meaningful progresses to the goal of the human-centric optoelectronics, significant challenges still exist toward high-performance soft light emitting devices and curved photodetector arrays. In this talk, material assembly and fabrication strategies for the soft human-centric optoelectronics will be presented. First, recent processes in flexible, foldable, and stretchable quantum-dot light emitting diodes (QLEDs) will be presented. Technologies for high-resolution quantum dot patterning as well as passive matrix array of QLEDs with unconventional form factors will be explained. After that, wide FoV, miniaturized module-size, minimal optical-aberration, high-sensitivity, and deep depth-of-field artificial vision systems inspired from aquatic animal eyes will be presented. Unique stretchable image sensors whose image planes are well matched to the single-lens-based optical system enable such artificial visions. More recent progresses in the bio-inspired artificial visions with amphibious imaging and light-balancing capabilities will be also explained. These deformable QLEDs and bio-inspired artificial visions are expected to provide new opportunities for the advanced mobile electronics and robotics.

November 27 2023 (Monday) 4:00-5:00pm
Professor Gregory Abowd have been speaking and writing about the idea of an Internet of Materials (IoM) for nearly a decade. It started as a way to rethink Mark Weiser’s vision of ubiquitous computing in a more modern context, with the same hopeful zeal that Weiser presented in his writings from the late 1980s and early 1990’s. Professor Abowd will summarize how that re-interpretation has inspired his work, and the work of a growing community, for nearly a decade. From those involved in the fundamental understanding of computation to those involved in the practical development and deployment of computation, the future seems bright. We are moving towards a world of increased ubiquity of computation. There appears to be no end in sight for the increased ubiquity of all things computational. From a technical perspective, this is wonderful. More recently, professor Abowd have been forced to think about this vision through a different lens. How we justify any new vision of a technological future must be better grounded in the human motivation and potential impact. After explaining the “successes” of IoM, he will explain why he has fallen far short of a compelling motivation. But there are more compelling motivations, having to do with health, usable security and privacy, and, most importantly, sustainability. We MUST begin questioning a lot of the assumptions on how to make, operate, and dispose of computational objects. IoM is no longer a journey for a hopeful “visionary” to play out his fanciful predictions for the future. It is a mandate to address the fundamental hazards of our current trajectory towards ubiquitous computing.

November 13 2023 (Monday) 3:00-4:00pm
The number of colors in fluorescence microscopy is far less than the types of intracellular compartments. I will present our recent progress in super resolution imaging and deep convolutional neuronal networks to segment 15 subcellular structures. This approach bypasses the limitations of multi-color imaging, accelerates the imaging speed by one order of magnitude, and can accurately segment vesicle organelles with similar shapes and sizes. The super-resolution advantages were demonstrated in resolving the 3D anatomic nanostructures at different mitotic phases and tracking the fast dynamic interactions among nine intracellular compartments in live cell. We show transfer learning ability of our networks among different microscopes, different cell types, and even complexed system of living tissues.

By integrating sensing, memory and processing functionalities, biological nervous systems are energy and area efficient. Emulating such capabilities in artificial systems is, however, challenging and is limited by the device heterogeneity of sensing and processing cores., Here, we present a universal solution to simultaneously perform multi-modal sensing, memory and processing using organic electrochemical transistors. The device has a vertical traverse architecture and a crystalline–amorphous channel that can be selectively doped by ions to enable two reconfigurable modes: volatile receptor and non-volatile synapse. As a volatile receptor, the device is capable of multi-modal sensing, and as a non-volatile synapse, it is capable of 10-bit analogue states, low switching stochasticity and good state retention. Homogeneous integration of such devices enables functions such as conditioned reflex and real-time cardiac disease diagnose via reservoir computing, illustrating the promise for future edge AI hardware.

Metals usually exist in form of polycrystalline solids, in which the networks of disordered grain boundaries tend to get eliminated through grain coarsening upon heating or straining, or to transform into metastable amorphous states when the grains are small enough. This is why nano-grained structures in metals are much more unstable relative to their coarse-grained counterparts. Through experiments and molecular dynamic simulations, we recently discovered a novel metastable structure in metals with grains of few nanometers in size, namely Schwarz crystal structure. The GB-network of the metal is characterized by 3D minimal interfaces structure with a zero-mean-curvature constrained by twin boundaries. The unique structure is thermally stable against grain coarsening at temperatures close to the equilibrium melting point and exhibits a hardness in vicinity of the theoretical value. The across-boundary diffusion is so effectively suppressed that the diffusion-controlled processes such as intermetallic precipitation are inhibited. In this presentation, Professor Ke Lu will introduce the formation process, structure characteristics, and some properties of the Schwarz crystal structures in a number of pure metals and alloys.