James C. Weaver

Instances of convergent or parallel evolution provide a potent model system for exploring contingency and determinism in evolutionary biology. Likewise, the multiple, independent habitat transitions from saltwater to freshwater biomes offer opportunity for studying convergent evolution within and among different vertebrate lineages. For example, stingrays have invaded freshwater habitats multiple times across different continents, sometimes even several times within the same clade (e.g., Dasyatidae). We evaluated the frequency of saltwater-freshwater invasions in stingrays, compared ecological and phenotypic diversification among freshwater and saltwater lineages, and assessed the degree of convergence among freshwater species. Despite not being morphologically distinct from saltwater stingrays, freshwater stingrays do expand the margins of stingray morphological diversity. According to our data …

Generating strong rapid adhesion between hydrogels has the potential to advance the capabilities of modern medicine and surgery. Current hydrogel adhesion technologies rely primarily on liquid-based diffusion mechanisms and the formation of covalent bonds, requiring prolonged time to generate adhesion. Here, we present a simple and versatile strategy using dry chitosan polymer films to generate instant adhesion between hydrogel–hydrogel and hydrogel–elastomer surfaces. Using this approach we can achieve extremely high adhesive energies (>3,000 J/m2), which are governed by pH change and non-covalent interactions including H-bonding, Van der Waals forces, and bridging polymer entanglement. Potential examples of biomedical applications are presented, including local tissue cooling, vascular sealing, prevention of surgical adhesions, and prevention of hydrogel dehydration. We expect these …

The large-scale implementation of renewable energy systems necessitates the development of energy storage solutions to effectively manage imbalances between energy supply and demand. Herein, we investigate such a scalable material solution for energy storage in supercapacitors constructed from readily available material precursors that can be locally sourced from virtually anywhere on the planet, namely cement, water, and carbon black. We characterize our carbon-cement electrodes by combining correlative EDS–Raman spectroscopy with capacitance measurements derived from cyclic voltammetry and galvanostatic charge-discharge experiments using integer and fractional derivatives to correct for rate and current intensity effects. Texture analysis reveals that the hydration reactions of cement in the presence of carbon generate a fractal-like electron-conducting carbon network that permeates the load …

Addressing the existing gap between currently available mitigation strategies for greenhouse gas emissions associated with ordinary Portland cement production and the 2050 carbon neutrality goal represents a significant challenge. In order to bridge this gap, one potential option is the direct gaseous sequestration and storage of anthropogenic CO2 in concrete through forced carbonate mineralization in both the cementing minerals and their aggregates. To better clarify the potential strategic benefits of these processes, here, we apply an integrated correlative time- and space-resolved Raman microscopy and indentation approach to investigate the underlying mechanisms and chemomechanics of cement carbonation over time scales ranging from the first few hours to several days using bicarbonate-substituted alite as a model system. In these reactions, the carbonation of transient disordered calcium …

Tunicates are an evolutionarily significant subphylum of marine chordates, with their phylogenetic position as the sister-group to Vertebrata making them key to unraveling our own deep time origin. Tunicates greatly vary with regards to morphology, ecology, and life cycle, but little is known about the early evolution of the group, e.g. whether their last common ancestor lived freely in the water column or attached to the seafloor. Additionally, tunicates have a poor fossil record, which includes only one taxon with preserved soft-tissues. Here we describe Megasiphon thylakos nov., a 500-million-year-old tunicate from the Marjum Formation of Utah, which features a barrel-shaped body with two long siphons and prominent longitudinal muscles. The ascidiacean-like body of this new species suggests two alternative hypotheses for early tunicate evolution. The most likely scenario posits M. thylakos belongs to stem-group …

Aortic stenosis (AS) affects about 1.5 million people in the United States and is associated with a 5-year survival rate of 20% if untreated. In these patients, aortic valve replacement is performed to restore adequate hemodynamics and alleviate symptoms. The development of next-generation prosthetic aortic valves seeks to provide enhanced hemodynamic performance, durability, and long-term safety, emphasizing the need for high-fidelity testing platforms for these devices. We propose a soft robotic model that recapitulates patient-specific hemodynamics of AS and secondary ventricular remodeling which we validated against clinical data. The model leverages 3D-printed replicas of each patient’s cardiac anatomy and patient-specific soft robotic sleeves to recreate the patients’ hemodynamics. An aortic sleeve allows mimicry of AS lesions due to degenerative or congenital disease, whereas a left ventricular sleeve …

Soft robots adapt passively to complex environments due to their inherent compliance, allowing them to interact safely with fragile or irregular objects and traverse uneven terrain. The vast tunability and ubiquity of textiles has enabled new soft robotic capabilities, especially in the field of wearable robots, but existing textile processing techniques (e.g., cut‐and‐sew, thermal bonding) are limited in terms of rapid, additive, accessible, and waste‐free manufacturing. While 3D knitting has the potential to address these limitations, an incomplete understanding of the impact of structure and material on knit‐scale mechanical properties and macro‐scale device performance has precluded the widespread adoption of knitted robots. In this work, the roles of knit structure and yarn material properties on textile mechanics spanning three regimes–unfolding, geometric rearrangement, and yarn stretching–are elucidated and …

A structural lattice includes a rectangular base defined by four periphery beams, and two non-diagonal beams that divide the rectangular base in four quadrants. The structural lattice further includes a diagonal reinforcement strut system overlaid on the rectangular base and having at least two intersecting sets of diagonal beams forming an open-and-closed cell architecture.

Ancient Roman concretes have survived millennia, but mechanistic insights into their durability remain an enigma. Here, we use a multiscale correlative elemental and chemical mapping approach to investigating relict lime clasts, a ubiquitous and conspicuous mineral component associated with ancient Roman mortars. Together, these analyses provide new insights into mortar preparation methodologies and provide evidence that the Romans employed hot mixing, using quicklime in conjunction with, or instead of, slaked lime, to create an environment where high surface area aggregate-scale lime clasts are retained within the mortar matrix. Inspired by these findings, we propose that these macroscopic inclusions might serve as critical sources of reactive calcium for long-term pore and crack-filling or post-pozzolanic reactivity within the cementitious constructs. The subsequent development and testing of modern lime clast–containing cementitious mixtures demonstrate their self-healing potential, thus paving the way for the development of more durable, resilient, and sustainable concrete formulations.

The remarkably complex skeletal systems of the sea stars (Echinodermata, Asteroidea), consisting of hundreds to thousands of individual elements (ossicles), have intrigued investigators for more than 150 years. While the general features and structural diversity of isolated asteroid ossicles have been well documented in the literature, the task of mapping the spatial organization of these constituent skeletal elements in a whole-animal context represents an incredibly laborious process, and as such, has remained largely unexplored.To address this unmet need, particularly in the context of understanding structure–function relationships in these complex skeletal systems, we present an integrated approach that combines micro-computed tomography, automated ossicle segmentation, data visualization tools, and the production of additively manufactured tangible models to reveal biologically relevant structural data …

Motivated by the need to develop more informative and data-rich patient-specific presurgical planning models, we present a high-resolution method that enables the tangible replication of multimodal medical data. By leveraging voxel-level control of multimaterial three-dimensional (3D) printing, our method allows for the digital integration of disparate medical data types, such as functional magnetic resonance imaging, tractography, and four-dimensional flow, overlaid upon traditional magnetic resonance imaging and computed tomography data. While permitting the explicit translation of multimodal medical data into physical objects, this approach also bypasses the need to process data into mesh-based boundary representations, alleviating the potential loss and remodeling of information. After evaluating the optical characteristics of test specimens generated with our correlative data-driven method, we culminate …

Implantable tubes, shunts, and other medical conduits are crucial for treating a wide range of conditions from ears and eyes to brain and liver but often impose serious risks of device infection, obstruction, migration, unreliable function, and tissue damage. Efforts to alleviate these complications remain at an impasse because of fundamentally conflicting design requirements: Millimeter-scale size is required to minimize invasiveness but exacerbates occlusion and malfunction. Here, we present a rational design strategy that reconciles these trade-offs in an implantable tube that is even smaller than the current standard of care. Using tympanostomy tubes (ear tubes) as an exemplary case, we developed an iterative screening algorithm and show how unique curved lumen geometries of the liquid-infused conduit can be designed to co-optimize drug delivery, effusion drainage, water resistance, and biocontamination …

At Abu Hureyra, a well-studied archeological site in Syria, the onset boundary of the Younger Dryas climatic episode ~12,800 years ago has previously been proposed to contain evidence supporting a near-surface cosmic airburst impact that generated temperatures >2000°C. Here, we present a wide range of potential impact-related proxies representing the catastrophic effects of this cosmic impact that destroyed the village. These proxies include nanodiamonds (cubic diamonds, n-diamonds, i-carbon, and lonsdaleite-like crystals); silica-rich and iron-rich micro-spherules; and melted chromite, quartz, and zircon grains. Another proxy, meltglass, at a concentration of 1.6 wt% of bulk sediment, appears to have formed from terrestrial sediments and was found to partially coat toolmaking debitage, bones, and clay building plaster, suggesting that village life was adversely affected. Abundant meltglass fragments examined display remarkably detailed imprints of plant structures, including those of reeds. The nanodiamonds are proposed to have formed under anoxic conditions from the incineration of plant materials during high-temperature, impact-related fires, while geochemical evidence indicates that the micro-spherules formed from the melting of terrestrial sediments. Broad archeological and geochemical evidence supports the hypothesis that Abu Hureyra is the oldest known archeological site catastrophically destroyed by cosmic impact, thus revealing the potential dangers of such events.

Effective masking policies to prevent the spread of airborne infections depend on public access to masks with high filtration efficacy. However, poor face-fit is almost universally present in pleated multilayer disposable face masks, severely limiting both individual and community respiratory protection. We developed a set of simple mask modifications to mass-manufactured disposable masks, the most common type of mask used by the public, that dramatically improves both their personalized fit and performance in a low-cost and scalable manner. These modifications comprise a user-moldable full mask periphery wire, integrated earloop tension adjusters, and an inner flange to trap respiratory droplets. We demonstrate that these simple design changes improve quantitative fit factor by 320%, triples the level of protection against aerosolized droplets, and approaches the model efficacy of N95 respirators in preventing the community spread of COVID-19, for an estimated additional cost of less than 5 cents per mask with automated production.

METHODS:Computer vision technology was used to develop an algorithm for near continuous, automatic, and marker-less image registration. The program fuses a subject’s pre-procedure CT scan to live 3D camera images (Snap-Surface), and movement is incorporated by artificial intelligence driven recalibration (Real-Track). Surface registration error (SRE) and target registration error (TRE) were calculated for five cadaver heads that underwent serial movements (fast and slow velocity roll, pitch, and yaw motions), and several test conditions. Six catheters were placed in each cadaver (30 placements). Post-procedure CT scans allowed comparison of planned and actual catheter position for user error calculation.RESULTS:Registration was successful for all five cadaveric specimens (average SRE 0.429 mm,±0.108). Accuracy of TRE was under 1.2 mm throughout specimen movements of low and high velocities …

As more roboticists are turning to Nature for design inspiration, it is becoming increasingly apparent that multisystem-level investigations of biological processes can frequently lead to unexpected advances in the development of experimental research platforms. Inspired by these efforts, we present here a holistic approach to developing an autonomous starfish-inspired soft robot that embodies a number of key design, fabrication, and actuation principles. These key concepts include integrated and sequentially deployable magnetic tube feet for site-specific and reversible substrate attachment, individually addressable flexible arms, and highly efficient and self-contained fluidic engines. These individual features offer a level of synergistic motion control not previously seen in other starfish-inspired robots. For example, our bistable dome-like tube feet are capable of achieving high adhesion forces to ferrous surfaces …

Traditional bolus vaccines often fail to sustain robust adaptive immune responses, typically requiring multiple booster shots for optimal efficacy. Additionally, these provide few opportunities to control the resulting subclasses of antibodies produced, which can mediate effector functions relevant to distinct disease settings. Here, it is found that three scaffold‐based vaccines, fabricated from poly(lactide‐co‐glycolide) (PLG), mesoporous silica rods, and alginate cryogels, induce robust, long‐term antibody responses to a model peptide antigen gonadotropin‐releasing hormone with single‐shot immunization. Compared to a bolus vaccine, PLG vaccines prolong germinal center formation and T follicular helper cell responses. Altering the presentation and release of the adjuvant (cytosine‐guanosine oligodeoxynucleotide, CpG) tunes the resulting IgG subclasses. Further, PLG vaccines elicit strong humoral responses …

Cellular solids (e.g., foams and honeycombs) are widely found in natural and engineering systems because of their high mechanical efficiency and tailorable properties. While these materials are often based on polycrystalline or amorphous constituents, here we report an unusual dual-scale, single-crystalline microlattice found in the biomineralized skeleton of the knobby starfish, Protoreaster nodosus. This structure has a diamond-triply periodic minimal surface geometry (lattice constant, approximately 30 micrometers), the [111] direction of which is aligned with the c-axis of the constituent calcite at the atomic scale. This dual-scale crystallographically coaligned microlattice, which exhibits lattice-level structural gradients and dislocations, combined with the atomic-level conchoidal fracture behavior of biogenic calcite, substantially enhances the damage tolerance of this hierarchical biological microlattice, thus …

Throughout the ancient Roman empire, crushed ceramics were commonly used as additives for surface mortars that were in continuous or frequent contact with freshwater. Inspired by the long-term durability of these materials and employing multi-scale correlative characterization approaches that combine electron microscopy and Raman microspectroscopy-based techniques, we demonstrate the role of these ceramics as a long-term source of reactive aluminosilicates. By mapping the spatial distribution of both pozzolanic and post-pozzolanic phases, our analyses reveal the presence of a hybrid binder consisting of cementitious hydrates and calcite at the interface between the ceramics and the surrounding matrix and provide evidence of post-pozzolanic densification and the filling of pores and cracks. The analysis of a wide range of ancient Roman structures used for the distribution and storage of freshwater …

Porous materials with well-defined periodicity are commonly encountered in biological and synthetic structures and exhibit a wide range of behaviors, ranging from negative Poisson’s ratios, to high energy absorption and acoustic damping. Recently, the response of these systems has been shown to be enhanced by mechanical instabilities that lead to sudden and reversible geometric transformations. Although buckling induces planar transformations in most of 2D porous metamaterials, here we describe the emergence of 3D morphologies triggered by mechanical instabilities in an elastomeric block with tilted cylindrical holes. As a proof of concept, we demonstrate that these structures can be leveraged to tune surface properties including friction and light reflection, thus providing a new experimental platform for investigating deformation-dependent dynamics for tribological and optical applications.