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1. Brief Paper: Geometric Determinants of Material Jetting-Enabled Bi-Material Interface Integrity Using Polyjet 3D Printing

   https://doi.org/10.1115/MSEC2024-122414  

   Aberdeen, Nolan J; Forghani, Kimia; Sochol, Ryan D (June 2024, American Society of Mechanical Engineers)

   Abstract Among the wide range of additive manufacturing — or “three-dimensional (3D) printing” — technologies, “material jetting” approaches are distinctively suited for multi-material fabrication. Because material jetting strategies, such as “PolyJet 3D printing”, harness inkjets that allow for multiple photopolymer droplets (and sacrificial support materials) to be dispensed in parallel to build 3D objects, distinct materials with unique properties can be readily unified in a single print akin to combining multiple-colored inks using a conventional 2D color printer. Although researchers have leveraged this multi-material capability to achieve, for example, 3D functionally graded and bi-material composite systems, there are cases in which the interface between distinct materials can become a key region of mechanical failure if not designed properly. To elucidate potential design factors that contribute to such failure modes, here we investigate the relationship between the interface design and tensile mechanical failure dynamics for PolyJet-printed bi-material coupons. Experimental results for a select set of bi-material sample designs that were 3D printed using a Stratasys Objet500 Connex3 PolyJet 3D printer and subjected to uniaxial tensile testing using a Tinius Olsen H25K-T benchtop universal testing machine under uniaxial strain revealed that increasing the surface contact area between two distinct materials via changes in geometric design does not necessarily increase the interface strength based on the length scales and loading conditions investigated in the current study and that further studies of the role of multi-material geometric designs in interface integrity are warranted to understand potential mechanisms underlying these results. Given the increasing interest in material jetting — and PolyJet 3D printing in particular — as a pathway to multi-material manufacturing in fields including robotics and fluidic circuitry, this study suggests that multi-material interface geometry should be considered appropriately for future applications. 

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2. Metabolic tagging of extracellular vesicles and development of enhanced extracellular vesicle based cancer vaccines

   https://doi.org/10.1038/s41467-023-43914-8  

   Bhatta, Rimsha; Han, Joonsu; Liu, Yusheng; Bo, Yang; Lee, David; Zhou, Jiadiao; Wang, Yueji; Nelson, Erik Russell; Chen, Qian; Zhang, Xiaojia Shelly; et al (December 2023, Nature Communications)

   Abstract As key mediators of cellular communication, extracellular vesicles (EVs) have been actively explored for diagnostic and therapeutic applications. However, effective methods to functionalize EVs and modulate the interaction between EVs and recipient cells are still lacking. Here we report a facile and universal metabolic tagging technology that can install unique chemical tags (e.g., azido groups) onto EVs. The surface chemical tags enable conjugation of molecules via efficient click chemistry, for the tracking and targeted modulation of EVs. In the context of tumor EV vaccines, we show that the conjugation of toll-like receptor 9 agonists onto EVs enables timely activation of dendritic cells and generation of superior antitumor CD8⁺T cell response. These lead to 80% tumor-free survival against E.G7 lymphoma and 33% tumor-free survival against B16F10 melanoma. Our study yields a universal technology to generate chemically tagged EVs from parent cells, modulate EV-cell interactions, and develop potent EV vaccines. 

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3. Micro‐Scale Device—An Alternative Route for Studying the Intrinsic Properties of Solid‐State Materials: The Case of Semiconducting TaGeIr

   https://doi.org/10.1002/anie.202002693  

   Antonyshyn, I.; Wagner, F. R.; Bobnar, M.; Sichevych, O.; Burkhardt, U.; Schmidt, M.; König, M.; Poeppelmeier, K.; Mackenzie, A. P.; Svanidze, E.; et al (March 2020, Angewandte Chemie International Edition)

   An efficient application of a material is only possible if we know its physical and chemical properties, which is frequently obstructed by the presence of micro‐ or macroscopic inclusions of secondary phases. While sometimes a sophisticated synthesis route can address this issue, often obtaining pure material is not possible. One example is TaGeIr, which has highly sample‐dependent properties resulting from the presence of several impurity phases, which influence electronic transport in the material. The effect of these minority phases was avoided by manufacturing, with the help of focused‐ion‐beam, a μm‐scale device containing only one phase—TaGeIr. This work provides evidence for intrinsic semiconducting behavior of TaGeIr and serves as an example of selective single‐domain device manufacturing. This approach gives a unique access to the properties of compounds that cannot be synthesized in single‐phase form, sparing costly and time‐consuming synthesis efforts. 

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4. Terahertz-readable laser engraved marks as a novel solution for product traceability

   https://doi.org/10.1038/s41598-023-39586-5  

   Hoveida, Pouria; Phoulady, Adrian; Choi, Hongbin; May, Nicholas; Shahbazmohamadi, Sina; Tavousi, Pouya (December 2023, Scientific Reports)

   Abstract Counterfeit products pose significant economic, security, and health risks. One approach to mitigate these risks involves establishing product provenance by tracing them back to their manufacturing origins. However, current identification methods, such as barcodes and RFIDs, have limitations that make them vulnerable to counterfeiting. Similarly, nonvolatile memories, physically unclonable functions, and emerging techniques like Diamond Unclonable Security Tag and DNA fingerprinting also have their own limitations and challenges. For a traceability solution to gain widespread adoption, it must meet certain criteria, including being inexpensive, unique, immutable, easily readable, standardized, and unclonable. In this paper, we propose a solution that utilizes ultrashort pulsed lasers to create unique, unclonable, and immutable physical tags. These tags can then be read nondestructively using far-field Terahertz (THz) spectroscopy. The primary objective of this paper is to investigate the feasibility of our proposed approach. We aim to assess the ability to distinguish laser marks with varying depths, evaluate the sensitivity of THz reading to laser engraving parameters, examine the capacity to capture high-information-density marks, and explore the ability to capture subsurface tags. By addressing these aspects, our method holds the potential to serve as a universal solution for a wide range of traceability applications. 

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5. Password-Protected Threshold Signatures

   https://doi.org/10.1007/978-981-96-0891-1_6  

   Dziembowski, Stefan; Jarecki, Stanislaw; Kedzior, Pawel; Krawczyk, Hugo; Ngo, Chan Nam; Xu, Jiayu (December 2024, Springer Nature Singapore)

   Chung, KM; Sasaki, Y (Ed.)

   We witness an increase in applications like cryptocurrency wallets, which involve users issuing signatures using private keys. To protect these keys from loss or compromise, users commonly outsource them to a custodial server. This creates a new point of failure, because compromise of such a server leaks the user’s key, and if user authentication is implemented with a password then this password becomes open to an offline dictionary attack (ODA). A better solution is to secret-share the key among a set of servers, possibly including user’s own device(s), and implement password authentication and signature computation using threshold cryptography. We propose a notion of augmented password-protected threshold signature (aptSIG) scheme which captures the best possible security level for this setting. Using standard threshold cryptography techniques, i.e. threshold password authentication and threshold signatures, one can guarantee that compromising up to t out of n servers reveals no information on either the key or the password. However, we extend this with a novel property, that compromising even all n servers also does not leak any information, except via an unavoidable ODA attack, which reveals the key only if the attacker guesses the password. We define aptSIG in the Universally Composable (UC) framework and show that it can be constructed very efficiently, using a black-box composition of any UC threshold signature [13] and a UC augmented Password-Protected Secret Sharing (aPPSS), which we define as an extension of prior notion of PPSS [30]. As concrete instantiations we obtain secure aptSIG schemes for ECDSA (in the case of t=n-1) and BLS signatures with very small overhead over the respective threshold signature. Finally, we note that both the notion and our generic solution for augmented password-protected threshold signatures can be generalized to password-protecting MPC for any keyed functions. 

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