Development of eco-benign marine natural products based antifouling coatings (Dr.Rasapalli):
Dr. Rasapalli has been on working anti-biofilm materials and inhibitors for the last 12 years. His research received funding through two NSF MRI grants (CHE-1229339 and CHE-1429086), and Microbiotix, Inc. He currently plans to utilize, under a proposal submitted to Marine and UnderSea Technology Research Program (MUST) through Office of Naval Research, some of the antibiofilm leads of his lab for solving the macro biofouling issue. Marine biofouling represents a major economic concern for marine industries. There is no perfect solution to this age-old thorny problem yet. Extensive use of toxic and harmful compounds has led to sterner EPA regulations and triggered an urgent search for new antifouling (AF) strategies. Inspired by marine organisms’ strategies that keep their surface clean, he proposes to use marine natural compounds (MNPs) as antifouling agents. He proposes to fabricate MNP based nanomaterial coatings and surfaces to develop “Eco-Benign Marine Natural Products Based Antifouling Coatings”. Hypothesis: Nature inspired antibiofilm materials provide greener options to solve the biofouling selectively without affecting the flora and fauna of the marine ecology (shown in Figure 1). The intellectual merit of this project is the development of synthetic access to active modified natural products that are in turn fabricated into novel biomaterials that are suitable for coating applications. These eco-friendly antifouling materials would have broader impacts through several applications in marine and healthcare industries in addition to the shipping industry.
A Bio-inspired Approach to Overcome Flow Battery Design Challenges (Dr. Cappillino)
Nonaqueous Redox Flow Batteries (NRFB) are a technology with the potential to transform our energy-storage landscape, facilitating transition from fossil fuels to renewable energy. While conventional, aqueous flow batteries are limited in application to large-scale, stationary (i.e., grid) storage, NRFB have the potential to operate at much higher voltages. This broadens their scope to include portable and distributed energy storage.
Despite the potential of NRFB, instability of charge-carrying active-materials, leading to capacity fade and poor lifetime, remains a key challenge. A fundamentally important research question in NRFB development is whether the high-voltages necessary to compete with other battery technologies are possible without sacrificing the stability necessary for exhaustive redox cycling. To address this problem, Dr. Cappillino lab developed a bio-inspired scaffold for NRFB development based on a molecule known as Amavadin, which is naturally occurring in mushrooms (see Figure 2b). Extremely strong and selective vanadium-ion binding evolved naturally under selection pressure for the organisms to concentrate metal-ions against a steep gradient. While the molecule is redox-active, its modest potential must be increased through covalent modification. We hypothesize that novel, advanced battery active-materials in which hydrogen atoms are substituted with fluorine atoms will exhibit higher vanadium(iv/v) couples, yielding a high-potential, stable positive electrolytes for NRFB applications (see Figure 2a). The intellectual merit of this project is in establishing foundational principles for battery active-materials having high-voltage without sacrificing the stability required for deep redox cycling. Broader impacts include advancing knowledge to overcome barriers to NRFB design, enabling widespread implementation of sustainable energy sources and facilitating enhanced electrical-grid resilience.
In collaboration with the Naval Undersea Warfare Center, our research group is currently developing high energy-density NRFB electrolytes for use in unmanned, undersea vehicles (UUVs) by improving the solubility and open-circuit voltage of the first-generation NRFB described above. Energy storage is a critical component of UUV systems since on-board instruments and sensors rely on an electrical power source. A high energy-density, liquid energy storage system such as NRFB would meet the criteria for UUV energy storage, while offering several advantages over other battery technologies, including capability short- and long-duration storage and rapid recharge. This research thrust aligns with a strategic goal of UMassD, emphasizing the maritime blue economy of the SouthCoast of New England. An important aspect of this is providing hands-on STEM training to our undergraduates, making them more qualified to enter our local workforce with highly skilled positions.
Plasmonic Materials for Tunable Optical Camouflage (Dr. Wei-Shun Chang)
Optical camouflage has been widely deployed in the military to reduce the visibility of weapons and soldiers to potential thread. The currently deployed technologies rely on the passive camouflage technique, which adapts the color and texture of the combat units to the known environment. However, the passive camouflage is not functional when the local background changes. In the Chang lab, we will synthesize the plasmonic nanoparticles that exhibit large absorption and scattering cross-sections. The color of the nanoparticles can be tuned by their sizes, shapes, compositions, and surrounding environment. We will integrate the nanoparticles into an electro-optical device to achieve active control of the color change, which is the first step to realizing the tunable optical camouflage.
Damage Sensing in liquid-metal reinforced laminated composites (Dr. Chalivendra)
This project aims to enhance the fracture toughness and impact energy absorption (IEA) of liquid metal (LM) reinforced laminated composites. The droplets of liquid metal such as Indium or Gallium or mix of both will be dispersed in a polymer matrix embedded with carbon nanotubes (CNTs) before they are being infused into stack of laminates through vacuum infusion process. Double cantilever beam (DCB) specimen configuration will be used for mode-I fracture toughness measurements. A gas gun assembly for projectile impact will be used for IEA measurements. The effect of amount of LM on the both fracture toughness and IEA will be investigated. We hypothesize that LM particles arrest the crack growth in DCB specimens and slow down the projectile speed in impact experiments.
Computational Modeling of Additive Manufacturing Materials and Triboelectric Nanogenerators (Dr. Li)
Additive manufacturing (AM), or 3D printing, has emerged as a viable advanced manufacturing technology to produce complex materials and structures with desired geometries. Triboelectric nanogenerator (TENG), based on triboelectrification and electrostatic induction to convert mechanical energy into electricity, has attracted much attention recently as a flexible energy harvesting technique. They both show enormous promises in maritime applications for fabrications of high-performance materials and energy devices that meet the complicated and hostile ocean environments. A number of experimental studies have been performed to investigate the effects of input parameters (processing conditions of temperatures, printing speed, build orientation, and materials microstructures, etc.) on the output performance (tensile and fracture properties, energy conversion efficiency, and surface charge density). However, the state of the art is hindered by the complexity of process and design variabilities; thus, it remains at the trial-and-error stage with insufficient modeling guidance. In additive manufacturing, we will focus on the fused filament fabrication (FFF) of polymer composites, one of the most popular one attributing to the inexpensive cost, wide availability of feedstock materials, and production of lightweight components. In FFF process, a part is fabricated by the extrusion of filament materials which builds the part’s geometry along trajectories generated by slicing layers and infill tool-paths. This process introduces a locally heterogeneous and anisotropic microstructure formed by the pores and the weld lines among deposited filaments. Li hypothesizes that the AM process-induced material microstructure, porosity, part distortions, residual stress, as well as degree of bonding among various material and layer interfaces, jointly influence the deformation and fracture of 3D printed materials. Dr. Li plans to develop multiphysics and multiscale computational simulations of AM process, which is further integrated into an anisotropic damage model coupled with extended finite element method (XFEM) to simulate materials fracture. For triboelectric nanogenerators, we will use the hypothesis that the flexoelectricity of inhomogeneous strains at nanoscale asperities causes triboelectric charging. Dr. Li plans to integrate contact mechanics analysis with flexoelectric models under various micro/nano-structured interfaces for optimal design of triboelectric nanogenerators. The intellectual merit is to advance our fundamental understanding of the multiscale mechanisms in mechanical, thermal, electrical, and fracture properties of AM materials and TENG devices. The high-fidelity computational simulations enabled by the proposed research can help to fabricate high-performance structural components and energy devices out of widely used polymer materials in a variety of maritime applications.
Developing porous super-hydrophobic surfaces for saving fuels in maritime transportation (Dr. Ling)
Recent studies show that the highly water-repelling, super-hydrophobic surface (SHS) could potentially generate a significant amount of drag reduction in turbulent flows, and thus reduces the fuel cost in maritime transportation. However, achieving sustainable drag reduction by SHS remains a big challenge. The main reason is that the gas bubbles trapped on the SHS, which are the key for drag reduction, could be washed away by turbulent flows. One potential technology to overcome this challenge is by applying the super-hydrophobic coating on a porous material, i.e., a porous super-hydrophobic surface. The gas bubbles on the surface can then be replenished and sustained by injecting gas through the porous surface. This project aims to understand the effects of pore size and porosity of the porous material on the restoration of gas bubbles, and develop the optimal porous super-hydrophobic surface for saving fuels in maritime transportation.
Simulation and Modeling of Bio-Inspired Active Materials for Nonaqueous Redox Flow Batteries (Dr. Mayes)
Energy storage is a vital technology for unmanned undersea vehicles (UUVs) since on-board instruments and sensors rely on an electrical power source. Currently, UUVs are limited in their range and duration by the capacity of their batteries. Nonaqueous redox flow batteries (NRFB) are a promising class of electrical energy storage technology. Compared to their aqueous counterparts, these systems have the potential for much wider electrochemical windows, with energy density comparable to that of Li-ion batteries. They have the potential to meet several requirements for UUV application, exhibiting high-thermal stability, facile start-up, and excellent long-duration storage performance. NRFB are versatile form of energy storage, as they can be recharged in the manner of other secondary batteries but can also be rapidly recharged by exchanging the liquid electrolyte. However, NRFB progress has been hampered by poor electrolyte stability and low solubility. In this project, the Mayes group will employ a computational approach to identify high-solubility active materials based on bio-inspired redox molecule. Solubility can be calculated by comparing stabilization of the gas-phase ions upon solvation (μsolv) with that of the organization of the ions in the crystal lattice (μlatt). We hypothesize that short-chain, asymmetric alkylammonium cations would exhibit high solubility. The intellectual merit of this project is to provide insight into the factors most important in predicting solubility and to design highly soluble active materials not yet experimentally realized. One of the impacts of this work would be training the next-generation researchers literate in high-performance computing and machine learning who have interdisciplinary expertise in chemistry and theory.
Novel bi-functional composite materials for structural energy storage in marine systems (Dr. Shen)
An increasing number of electrically powered marine systems such as distributed sensors and autonomous underwater vehicles (AUVs) are being deployed in the oceans. The operation time, useful lifetime, and the overall size of such systems are still limited by the energy storage components (e.g. rechargeable batteries) that provides the power. Meanwhile, polymer matrix composite (PMC) materials are widely used as structural components in all kinds of naval systems partly due to their outstanding mechanical properties, lightweight and durability. Here we aim to develop novel bi-functional composites (shown in Figure 6) that integrate energy storage functionality into structural PMC for maritime applications. Previous studies have demonstrated structural supercapacitors, which is an electrochemical energy storage device, using ion-conducting resin as electrolytes and carbon fibers as electrodes. Supercapacitors outperforms batteries in terms of safety, stability, and operation lifetime. However, the reported devices show limited energy densities (<10 mWh/kg). Shen has worked on carbon fiber-solid electrolyte supercapacitor systems in the past years. Our work demonstrated gel electrolyte and activated carbon fiber electrode with more than two orders increase in energy and power densities (1-3 Wh/kg @ 10-100 W/kg), but the gel electrolyte/carbon fiber composite is not stiff enough for structural applications. The proposed project will experiment and design the synergistic electrochemical and mechanical effects of the bi-functional electrode-electrolyte systems. Our hypothesis is that the mechanical properties and energy storage performance of such composites can be tuned by adjusting the chemical composition of the electrolyte matrix and the surface property of the electrode filler. The intellectual merit is to understand the bi-functional interfaces in composites and design materials with practical energy and power densities (~10 Wh/kg @ 100 W/kg) and improved mechanical toughness. The broader impact is to provide a novel solution to improving the power supplies of all kinds of consumer, military, and space applications, by storing electricity in their structural frameworks.
Light Actuated Microbots: Design, Fabrication, and Manipulation in Fluids (Dr. Kihan Park)
Untethered mobile robots at the micro-scale have the ability to improve 
biomedical research by performing specialized tasks inside complex physiological environments. Light-controlled wireless microbots are becoming the center of interest thanks to their accuracy in navigation and potential to carry out operations in a non-invasive manner inside living environments. The pioneering light-engineered microbots are currently in the early stage of animal trials. Research showed the feasibility to employ them in humans for therapeutic applications such as targeted drug delivery, cancer cell diagnosis, tissue engineering, etc. We fabricate the microbots in MIT’s Fab.nano facility. Currently, we are trying to control these microbots in fluidic environments using modular optical tweezers from Thorlabs, equipped with a spatial light modulator (SLM) to trap and manipulate multiple optical traps. A python program is scripted for better controlling the traps with the SLM. An REU student is expected to take an independent role in this project regarding one of the followings: design / fabricate / characterize / control / testing microbots in various fluidic environments.
Bioinspired Photonic Materials Based on Iridescent C. Lytica Bacteria (Dr. Vasudev)
Naturally occurring photonic crystal structures have garnered significant interest due to their localized optical modes, which are known to enhance light-matter interactions. Nature has perfected the design of photonic structures, such as the ones seen in Morpho butterfly wings and beetle species such Chrysochroa. Recent advancements in nanoscience have generated significant interest in creating novel designer materials by “mimicking” naturally occurring nanostructures that can be used as building blocks in order to synthesize highly ordered polymeric materials with desirable properties. But most of the techniques utilized in the synthesis of such structures such as lithography (UV, electron beam) are time consuming, and expensive to generate and reproduce. Recently, glitter-like iridescence has been observed in various strains of cytophaga, flavobacterium, and bacteroides such as Cellulophaga lytica (shown in Figure 7). Localized short-range ordering in the bacteria was found to be replicated over large areas contributing to the iridescence due to the gliding motility of the bacteria as observed in the culture conditions. When the packing of bacteria is perfect leading to the formation of a 2D close-packed lattice, the colony diffracts light at specific angles of viewing. These bacteria will be studied to further understand their application as colorimetric sensors. The major objectives in this project are: (a) study of “glitter-like” iridescence in C. Lytica under controlled growth conditions such as temperature, and nutrients on the gliding motility and resultant dominant color produced in the bacterial culture, (b) study of the influence of physically constrained (such as micro-patterned arrays, grooves and channels) growth on the iridescence in C. Lytica, and (c) photonic material synthesis using bacterial building blocks. The proposed research work will address the following areas of interest (1) The fundamental growth conditions leading to the organization observed in C Lytica; (2) Investigation of methods by which the organization of the bacteria can be controlled and replicated; (3) Development of photonic materials using biological building blocks, which can be genetically modified in the future.
Mechanics of hollow and porous crushable granular materials (Dr. Beemer):
Dr. Beemer has been working on the mechanics of hollow and porous grained offshore calcareous soils (granular materials) for the past five years. This work has been done as part of their postdoctoral research work at the University of Western Australia, their Start-Up at the University of Massachusetts Dartmouth, and seed funding through Syracuse University/NSF (28250-04301-S25). Naturally hollow and porous biogenic calcareous sediments are common throughout of the low latitude areas of the world near the equator. These granular materials consist largely of skeletal remains of marine micro and macro-organisms. These sediments have been particularly problematic for offshore energy infrastructure as they exhibit high compressibility and friction angle softening when sheared. In this proposed project, PI plans to investigate the micromechanical behavior of crushable hollow biogenic calcareous sediment previously collected from offshore North West Australia under different modes of shearing: triaxial shear, direct shear, and interface shear. Crushing would quantified through changes to the cumulative distribution function of particle size, optical imaging, and X-ray microtomography. Beemer hypothesizes that “the crushing of hollow and porous granular material results in an increase of extra-particle void ratio; increasing bulk compressibility and potentially shear strength. This is due to the introduction of intraparticle voids to the bulk system as particles implode” The intellectual merit of this project is to experimentally investigate and quantify the micromechanics behaviors that lead to high compressibility and strength reduction in crushable hollow and porous granular materials. Understanding the behavior of these granular materials have broader impacts through the design and construction of coastal and offshore infrastructure in biogenic calcareous sands which are naturally porous and hollow.
Optimal design of meta-materials for source localization using machine learning techniques (Dr. Louhghalam):
Dr. Louhghalam has been studying ways to enhance the efficiency of source localization using low frequency locally resonant materials (LFLRM). The research is currently supported by Marine and UnderSea Technology Research Program (MUST) through Office of Naval Research (N00014-20-1-2170). Source localization is a complex problem with many applications including navigation, and surveillance among others [143-144]. Passive localization is usually performed through measuring the acoustic signals via array of sensors embedded in a homogenous isotropic material. The collective data acquired by the sensor array is analyzed e.g. in the simplest way through beam-forming approaches [145], to determine the bearing angle of the source. The performance of vector sensor array, in a first order analysis is limited by the physical size of the array. Furthermore, vibrations of the vehicle carrying sensors result in low-frequency noise and lead to low SNR. The goal of this proposed project is to enhance source localization techniques through leveraging the advancements in low frequency locally resonant metamaterials (LFLRM) [146] and machine learning and optimization techniques to significantly enhance the localization performance of sensor arrays. We plan to replace the homogenous isotropic panels with a locally resonant micro-structure. Hypothesis: The presence of other resonance modes in such systems would lead to a more selective response of the beamforming array, by modifying the wave number in plane of the array and filtering out stop band frequency ranges that may introduce noise into the measurements. Dr. Louhghalam’s team have been developing multi-physics models to study the response of LFLRMs in presence of an acoustic planar wave. The plan is to combine these physics-based models with machine learning techniques for training a predictive model for source localization. Intellectual merit: The proposed method in an integration of multi-physics modeling with machine techniques for enhancing the prediction accuracy of bearing angle of the acoustic source. Broader Impact: The successful implementation of this project will significantly enhance the existing source localization approaches design of metamaterials for increased resolution and SNR.