Materials Science and Engineering Commons^™

Microstructural Changes And Residual Stress Generation On The Periodically Patterned Surface Texture Fabricated By Angled Fine Particle Peening, Yutaka Kameyama, Hideaki Sato, Ryokichi Shimpo

15th International Conference on Shot Peening

Focusing on the potential of peening technology as a surface texturing technique, angled fine particle peening (angled-FPP) has been proposed to fabricate a specific periodical surface structure, which possibly provides various surface functions. It is necessary to further characterize the textured surface to earn more advantages from angled-FPP. Thus, in this paper, texture formation phenomena, residual stress, and microstructural changes were investigated on the angled-FPP specimens.

Methodologies And Applications Of Precision Shot Peening To Hole Or Slot Geometry, James C. Hoffman

15th International Conference on Shot Peening

Shot peening, a commonly used method of fatigue and surface enhancement, is a critical process in many of the components in the aerospace industry. When it comes to small holes and/or slot geometries in these components, the process can become a challenge when these features are smaller than a conventional size Almen strip. In these cases, a decision must be made about how to process this type of geometry. Oftentimes, the method to apply the shot peen process is already defined in a process specification or part print so we must adhere to that method. If a method is not …

E-Strip® Peening Intensity Sensor - Linearity, Variability And Connectivity, Sylvain A. Forgues, Brigitte Labelle, Ramzi Ben Moussa, Sebastien Beaugrand, Raphael Sarraillon, Sergio Amaya

15th International Conference on Shot Peening

This paper presents the E-Strip®, a novel electronic sensor developed by Shockform to digitally measure shot peening intensity at the part level. Motivated by the limitations of traditional Almen strips—namely, manual handling, time consumption, and susceptibility to human error—the E-Strip® offers a faster, more reliable, and connected alternative. Extensive testing confirmed the E-Strip® output maintains excellent linearity with Almen intensity across a wide range of media and impact levels (R² > 0.997), and its adjustable sensitivity ensures compatibility from low to high intensities. Variability studies showed the E-Strip® provides similar or better consistency than Almen strips at low intensities, although higher …

Improving Fatigue Strength And Life Of Single Crystal Cmsx-4, Jochen Peter Fuhr, Lloyd Hackel, Nicolau I. Morar, Noah Holtham, Keivan Davami, Montu Sharma, Rajkumar Roy

15th International Conference on Shot Peening

The deep penetration of laser peening (LP) and retention of residual stress at high temperature by LP is significant in improving fatigue life and strength of superalloys exposed to high temperature and corrosion. Single crystal CMSX-4, was evaluated for stress relaxation and both fatigue life and fatigue strength of material that was LP-treated compared to non-LP and shot-peened (SP) specimens. LP was done with multiple layers using a 20 J/pulse laser where the laser high energy enabled using a 5 mm spot size on the metal surface. Stress measurements by the slitting technique showed the plastic penetration depth exceeded SP …

Application Of Burnishing Process Expected To Frictional Heat To Non-Oriented Electromagnetic Steel Sheet, Yuji Kobayashi, Masato Okada

15th International Conference on Shot Peening

Burnishing is a technology used to improve the surface roughness of metals. On the other hand, it is expected that the metal structure near the surface will change due to strong distortion.

The magnetic properties of electromagnetic steel sheets depend on large crystal grains and fine crystals near the surface[1]. In particular, thinner fine crystal grain layers on the surface are expected to reduce iron loss. In this study, the power generation characteristics of Burnished electromagnetic steel sheets were evaluated.

Electromotive force waveform was evaluated by rotating the laminated electromagnetic steel sheets and using a spindle motor. The electromotive force …

The Effects Of Shot Peening Highly Loaded Compression Springs, David J. Breuer

15th International Conference on Shot Peening

The compression spring in this test study is typical of one used in a demanding off-road vehicle suspension. The cyclic loads applied during fatigue tests were severe enough to cause failure in approximately 11,000 cycles without shot peening.

The objectives of this study were the following: (1) Design a compression spring similar to those used in the off-road recreational industry. (2) Design & manufacture a fatigue test stand that could withstand high loads for months of testing. (3) Generate a matrix of shot peening treatments to produce different amounts of residual compressive stress. (4) Measure the shot peening residual compressive …

Nonlinear Analytical Models Of The Seismically Isolated ``Frame-Boiler'' System With Cantilever-Type Hysteresis Dampers, Aleksandr Mikhailovich Anushchenko, Dmitrii Evgenievich Bondarev, Aleksandr Yurievich Schukin

Journal of Sustainable Construction Materials and Technologies

This study shows results of development of the ``frame-boiler'' system with hysteresis dampers analytical model. Hysteresis dampers are used as boiler antiseismic bracing. It is noted that simplified analytical models are necessary at the stage of preliminary iterative calculations, when a CAE-modeling is impractical due to significant time costs. The authors have proposed 2 options of analytical models: 2-mass model and 3-mass model. The differential equations of motion for each model are written below. The results of the calculation for seismic impacts are compared with the finite element model. It is shown that 3-mass model gives good match of results …

Advancing Sustainable Structural Solutions: Hemp Fiber-Reinforced Polymer (Hfrp) Reinforcement Bars For Concrete Applications Through Material Selection, Simulation, And Pathways For Future Development, Thomas Cadenazzi, Busra Keles

Journal of Sustainable Construction Materials and Technologies

This paper investigates innovative Hemp Fiber-Reinforced Polymer (HFRP) rebars as a sustainable alternative to conventional Carbon Steel (CS) and Glass Fiber-Reinforced Polymer (GFRP) rebars used as reinforcement in concrete structures. The feasibility of HFRP rebars is assessed, focusing on mechanical properties and sustainability advantages. A virtual tensile test on a modeled M19 HFRP rebar, conducted using Autodesk's Fusion 360, demonstrates tensile strength comparable to CS 235 and greater environmental sustainability than GFRP, despite a slight reduction in stiffness. The study also considers the potential of graphene fiber integration to enhance mechanical properties, underscoring HFRP's adaptability. Findings suggest that HFRP rebars, …

Overcoming Variable Illumination In Photovoltaic Snow Monitoring: A Real-Time Robust Drone-Based Deep Learning Approach, Amna Mazen, Ashraf Saleem, Kamyab Yazdipaz, Ana Dyreson

Michigan Tech Publications

Snow accumulation on photovoltaic (PV) panels can cause significant energy losses in cold climates. While drone-based monitoring offers a scalable solution, real-world challenges like varying illumination can hinder accurate snow detection. We previously developed a YOLO-based drone system for snow coverage detection using a Fixed Thresholding segmentation method to discriminate snow from the solar panel; however, it struggled in challenging lighting conditions. This work addresses those limitations by presenting a reliable drone-based system to accurately estimate the Snow Coverage Percentage (SCP) over PV panels. The system combines a lightweight YOLOv11n-seg deep learning model for panel detection with an adaptive image …

Unified Study Of The Classical Hall Effect, Carter J. Reed, Javier E. Hasbun, Wyatt E. Ackerman, L Ajith Desilva

Georgia Journal of Science

Germanium (Ge) samples with different doping types, acceptors (p-type) and donors (n-type), were studied to investigate charge carrier behavior. Carrier concentrations were found to be 1.16×10^21 m^(-3) for the p-type sample and 7.337×10^20 m^(-3) for the n-type sample. These experiments were conducted for the standard Hall effect (Hall voltage versus low magnetic field (B) values) as well as conductivity and Hall voltage versus temperature for different B-fields. The measurements versus temperature at zero-field allow us to obtain band gap ( Eg). While we investigate the conductivities for n-type and p-type doped samples, we also study the conductivity of an undoped …

Comparative Analysis Of Life Cycle Assessment Of Traditional And Contemporary Timber Buildings, Sadık Akşar, Gökçe Tuna

Journal of Sustainable Construction Materials and Technologies

Wood has long been used as a primary building material, but with the Industrial Revolution and the spread of multi-story structures, its structural limitations became evident. In the 21st century, engineered timber products have reintroduced wood as a sustainable alternative, offering advantages such as lightness, rapid assembly, and recyclability. At the same time, buildings are responsible for significant environmental impacts, making assessment methods essential. Life Cycle Assessment (LCA) is one of the most widely used tools for evaluating these impacts across all stages of a building’s life cycle. This study applies LCA to timber construction systems, focusing on both traditional …

Sustainable Paving Block Development: Utilizing Rejected Coal As Filler And Assessing Its Impact On Paving Block’S Properties, Siti Nikmatin, Allen Kurniawan, Heriansyah Putra, Rima Fitria Adiati, Riawan Ma’Ruf, Dwi Arso Yedi Irwanto

Journal of Sustainable Construction Materials and Technologies

This study investigated the potential use of rejected coal as a fine aggregate filler in paving block production. Comprehensive characterization of the rejected coal was conducted, including toxicity, physical, chemical, and mineralogical analyses of the coal. The results showed that the rejected coal met environmental safety standards (TCLP) and had suitable properties as an aggregate. Paving blocks were produced by incorporating different proportions of rejected coal fillers and were tested for compressive strength, water absorption, and density. The optimal mix with 35% rejected coal filler as a replacement of stone ash achieved a compressive strength of 14.61 MPa, water absorption …

Numerical Comparative Study Of The Thermal Performance And Load-Bearing Capacity Of Hollow Clay Bricks Used In Construction In Libya, Osama Lawej, Mahmoud Ahmed, Ismael Ehtiwesh

Journal of Sustainable Construction Materials and Technologies

The optimization of structural and thermal performance in building components is a key challenge in sustainable construction, particularly in hot climate regions like Libya. Hollow clay bricks are widely used due to their local availability and affordability; however, their internal geometry is often not optimized for thermal resistance or mechanical integrity. This study addresses this gap by numerically investigating the effect of cavity geometry on the load-bearing capacity and thermal insulation performance of hollow clay bricks. Three configurations were analyzed, including two commercial designs from the Libyan market and a newly proposed arched cavity design. Finite Element Method (FEM) simulations …

Developing A Modular Circular Wall Over-Clad System For Facade Thermal Upgrade In Deep Energy Retrofit, Patrick Daly

Journal of Sustainable Construction Materials and Technologies

The EU has implemented several policy and legislative initiatives aimed at decarbonisation and circularity transition of the Built Environment including a strategy for large scale renovation of the building / housing stock. Modularised construction solutions are argued to be a potential acceleration pathway toward this objective. Yet there remains issues and challenges in implementing such strategies in a complex and heterogeneous stock and sector. This research investigates this decarbonisation pathway, examining the feasibility and potential of applying a modularised construction over-clad system, based on advanced circularity, in the deep energy retrofit of social housing. The research is based on a …

Effect Of Gelam Wood And Rice Husk Composition With Molding Pressure On The Combustion Performance Of Biopellets, Rachmat Subagyo, Rudi Siswanto, Ma’Ruf Ma’Ruf, Mastiadi Tamjidillah, Abdul Ghofur, Femiana Gapsari, M. Zainul Rusdi, Azie Aprianto, Wardoyo Wardoyo, Naila Salsabila

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigates the effects of gelam wood (Melaleuca leucadendron) and rice husk composition in biopellet production, focusing on compaction pressures of 60, 80, and 100 kg/cm². Five biomass ratios (G100–RH0, G80–RH20, G60–RH40, G50–RH50, G0–RH100) were tested for moisture, ash, fixed carbon, volatile matter, calorific value, ignition time, burning rate, and combustion temperature. Results showed that moisture content ranged from 0.98% (G0–RH100, 60 kg/cm²) to 12.28% (G100–RH0, 80 kg/cm²), while ash content varied between 2.47% (G100–RH0, 60 kg/cm²) and 20.93% (G0–RH100, 80 kg/cm²). The highest calorific value reached 3968 cal/g (G100–RH0, 60–80 kg/cm²), though below the SNI 8675:2018 minimum of …

Ferric Metal-Organic Frameworks (Mofs)-Based Electrospinning Fibers For Supercapacitors, Samar A. Salim, Hani Nasser Abdelhamid

Nanotechnology Research Centre

Ferric-based metal-organic frameworks (Fe-MOFs) were synthesized and incorporated into poly(methyl methacrylate) (PMMA) using electrospinning to produce PMMA_Fe-MOF nanofibers. The materials were analyzed using X-ray diffraction (XRD), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), and scanning electron microscopy (SEM). The electrospun materials were directly integrated into nickel foam (NF) electrodes for energy storage applications, e.g., supercapacitors. The electrochemical performance was assessed using cyclic voltammetry (CV), galvanostatic charge-discharge curves (GCDC), linear sweep voltammetry (LSV), and electrochemical potentiokinetic reactivation (EPR). The PMMA_Fe-MOF electrodes exhibited outstanding capacitive performance, achieving specific capacitances of up to 1017.5 F/g at 1 A/g for the 2.5 % Fe-MOF …

Effect Of Graphene Nanoplatelets Fraction On The Microstructure And Mechanical Properties Of Inconel 718 Composites Prepared By Spark Plasma Sintering, Sanoj Karki, Manoj Mugale, Satyavan Digole, Amit Choudhari, Mayank Garg, Caleb Schenck, Fu-Yun Tsai, Bharat Gwalani, Tushar Borkar

Mechanical Engineering Faculty Publications

Nickel-based superalloy, particularly Inconel 718, is a promising candidate in advanced structural and high-temperature applications, including turbine blades, combustors, and turbochargers. However, high-efficiency energy systems such as jet engines and land-based gas turbines demand increasingly high strength for advanced structural applications. Therefore, significant efforts are underway to enhance the strength of these materials. Reinforcement of graphene nanoplatelet (GNP), owing to its exceptional mechanical strength, lightweight, high aspect ratio, and high level of coherency with metal matrix, has been proposed as an effective way of incorporating high strength into the existing Inconel 718. In addition, the spark plasma-assisted heating process is …

Enabling Carbon Dioxide Mineralization And Active Set Control In Portlandite-Based Cementitious Suspensions, Xiaodi Dai, Sharu Bhagavathi Kandy, Rui Xiao, Manas Sarkar, Shubham Wani, Thiyagarajan Ranganathan, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gädt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

The real-time control of concrete's stiffening allows users to better control pumping and extrusion during 3D-printing processes. Here, a portlandite-based cementitious formulation (i.e., slurry or suspension) that features the potential for rapid CO₂ uptake is adapted for 3D-printing applications. In particular, we showcase a portlandite-fly ash binder system combined with a thermo responsive polymer, wherein precise control via thermal activation allows set control and rapid solidification. Through the thermally induced polymerization of polyacrylamide, the hybrid binder system rapidly undergoes stiffening at trigger onset temperatures ranging from 60 °C to 80 °C, exhibiting average stiffening rates of up to 2600 …

Synergetic Adsorptive Mechanisms, Reusability And Cost Evaluations Of Green Fabricated Hybrid Barium Cobalt Nanocomposites For Methylene Blue And Lead Removal From Wastewater, Titus Chinedu Egbosiuba, Chibuike Christogonus Njoku, Ijeoma Jacinta Ani, Godwin Ifeanyi Ogbuehi, Abdulkareem Omeiza Yusuf, Abiodun Azeez Saka, Ugochukwu Ewuzie, Ebuka Emmanuel Ezennajiego, Blessing Onyinye Okafor, Walter Chibuike Anene, Cecilia Chika Unegbu, Florence Acha, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Barium nanoparticles (BaNPs), cobalt nanoparticles (CoNPs), and hybrid barium-cobalt nanocomposites (BaCoNCs) were synthesized using an eco-friendly green technique with Anacardium occidentale leaf extract for sequestration of methylene blue (MB) dye and lead (Pb (II)) ions from industrial wastewater. The nanoparticles and nanocomposites were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM), and Brunauer-Emmett-Teller (BET) analysis to assess their functional groups, crystalline structure, morphology, and surface properties, confirming successful synthesis. Batch adsorption studies showed that optimal pollutant removal occurred at pH values of 8 for MB and 5 for Pb(II), with a contact time …

Tensile Creep Of A Hybrid Polymer-Matrix/Ceramic-Matrix Composite At Elevated Temperature, Waleed S. Alshehri

Theses and Dissertations

Advanced aerospace systems require structural materials that can perform reliably in high-temperature environments for long durations. The performance of standard polymer matrix composites (PMCs) in these conditions is often limited by their susceptibility to time-dependent deformation, such as creep. The objective of this research is to characterize the high-temperature creep behavior of a novel unitized material system comprising a polymer matrix composite (PMC) and a ceramic matrix composite (CMC) co-cured together. The PMC part consists of the polyimide matrix reinforced with laminated carbon fibers woven in an eight harness satin weave (8HSW). The CMC part consists of a zirconia-based ceramic …

In Situ High-Temperature Raman Spectroscopy For Online Eaf Slag Analysis, Bohong Zhang, Hanok Tekle, Ronald J. O'Malley, Jeffrey D. Smith, Farhan Mumtaz, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Real-time monitoring of slag chemistry is critical for optimizing Electric Arc Furnace (EAF) steelmaking operations, where dynamic variations in slag composition directly influence slag foaming, refractory degradation, and thermal efficiency. Conventional techniques such as X-ray fluorescence (XRF), Fourier-transform infrared (FTIR), and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) are commonly used to analyze slag composition, but their offline nature and equipment constraints limit their applicability for online monitoring in harsh industrial environments. To address this challenge, we present an in situ, high-temperature analytical approach that integrates Raman spectroscopy with a custom-designed fiber-optic probe for real-time slag characterization at …

Effect Of Contact Time And Concentration On Adsorption Of Pb2+Metal Ion Utilizing Crab Shell Chitosan And Activated Bentonite Clay Composite, Nia Sasria, Adi Wisaka, Ade Wahyu Yusariarta Putra Parmita, Gusti Umindya Nur Tajalla

Makara Journal of Technology

Indonesia produced 1,508 tons of nonliving crabs in the January–March 2020 period. The number of shells generated can account for 40%–60% of the overall weight. Therefore, using crab shells made into chitosan is expected to increase the economic value and reduce waste from crab shells. Chitosan can be modified with clay previously activated with an acid solution to form a chitosan–clay composite to improve the adsorption capacity. This study aims to analyze the differences in characteristics between chitosan and clay before and after the immobilization process. A comparison of chitosan and clay (1:2) is conducted on the basis of variations …

A Green Concrete Mixture Using Rice Husk As Partially Cement Replacement, Khloud Khalid Eldamshiry, Zeina Salama, Amany Micheal, Rania Rushdy Moussa, Ayatallah Raafat

Architectural Engineering

Egypt's agricultural waste production has increased significantly in recent decades, leading to improper disposal methods and environmental pollution. Rice husks are the most common agricultural solid waste in Egypt, contributing to "black clouds" and causing health issues. On the other hand, Cement, a crucial component of construction materials, generates unsound residues and greenhouse gas emissions. Green concrete with rice husks could be a profitable solution for environmentally sound construction, reducing cement consumption and increasing the durability and integrity of new materials. This study investigates the use untreated rice husk fibres with a concrete mixture, avoiding burning and contributing to environmental …

Piezoelectric Dc Generator Through Sequential In-Phase Polarization Variation, Hyun Soo Kim, Sunghoon Hur, In Woo Oh, Chulwan Lim, Huimin Qiao, Hyung Jin Choi, Min Seok Kim, Dae Sol Kong, Jong Hoon Jung, Joonchul Shin, Seung Hyub Baek, Jun Chen, Chong Yun Kang, Jeong Min Baik, Yu U. Wang, Shashank Priya, Seong H. Kim, Yunseok Kim, Hyung Suk Oh, Kyung Hoon Cho, Jungho Ryu, Hyun Cheol Song

Michigan Tech Publications

Energy harvesting has drawn growing interest as a reliable power source for IoT applications, with piezoelectric materials notable for their high sensitivity and straightforward integration. Their robust mechanical-electrical coupling also makes them ideal for harnessing environmental vibrations or mechanical motions. Still, standard piezoelectric harvesters inherently produce alternating current (AC), necessitating complex rectification steps and leading to substantial energy loss. This work introduces a direct current (DC) harvesting method that employs a novel in-phase polarization strategy, enabling a stable, continuous DC output. This approach surpasses prior attempts that offered only low or pulsed DC signals, achieving an open-circuit voltage of 33.44 …

Superhydrophilic Porous Coooh Nano-Architecture With Abundant Oxygen Vacancies For Enhanced Urea Electrooxidation At Ampere-Level Current Densities, Wen-Jing Lv, Xiao-Man Tang, Xue-Tong Wang, Wen-Cai Liu, Jian-Wen Zhu, Guo-Jing Wang, Yuan-Zhi Zhu

Journal of Electrochemistry

The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention. However, challenges remain, particularly with sluggish catalytic kinetics and limited long-term stability of urea oxidation reaction (UOR). Herein, we report the loosely porous CoOOH nano-architecture (CoOOH LPNAs) with hydrophilic surface and abundant oxygen vacancies (O_v) on carbon fiber paper (CFP) by electrochemical reconstruction of the CoP nanoneedles precursor. The resulting three-dimensional electrode exhibited an impressively low potential of 1.38 V at 1000 mA·cm⁻² and excellent durability for UOR. Furthermore, when tested in an anion exchange membrane (AEM) electrolyzer, it required only 1.53 V at …

First Principles Materials Discovery And Design For Photovoltaic And Solar Thermal Alloys Using High Throughput Methods, Andrew Pike

Dartmouth College Ph.D Dissertations

Materials selection has been a challenge since the dawn of time. With the advent of computational methods and high throughput databases, materials can be discovered and assessed before they are even synthesized. In this thesis I will discuss my work towards designing new materials for clean energy uses, especially alloys which have been underexplored from computational methods. To begin, I present a case study explaining the synthesis of the Yb₁₄ZnSb₁₁ thermoelectric material. Next, I explore the class of AM₂Pn₂ Zintl materials. From the previously identified BaCd₂P₂, it is suspected that …

Structure Regulation Engineering For Biomass-Derived Carbon Anodes Enabling High-Rate Dual-Ion Batteries, Rui Zhou, Rui Liu, Yun-Nuo Li, Si-Jie Jiang, Tian-Tian Jing, Yan-Song Xu, Fei-Fei Cao

Journal of Electrochemistry

Dual-ion batteries (DIBs) usually use carbon-based materials as electrodes, showing advantages in high operating voltage, potential low cost, and environmental friendliness. Different from conventional “rocking chair” type secondary batteries, DIBs perform a unique working mechanism, which employ both cation and anion taking part in capacity contribution at an anode and a cathode, respectively, during electrochemical reactions. Graphite has been identified as a suitable cathode material for anion intercalation at high voltages (> 4.8 V) with fast reaction kinetics. However, the development of DIBs is being hindered by dynamic mismatch between a cathode and an anode due to sluggish Li^{+ …}

Design And Optimization Of Anode Catalysts For Direct Ethanol Fuel Cells: Advances And Challenges In C-C Bond Activation And Selective Modulation Of The C1 Pathway, Kai-Chi Qin, Meng-Tian Huo, Yu Liang, Si-Yuan Zhu, Zi-Hao Xing, Jin-Fa Chang

Journal of Electrochemistry

Direct ethanol fuel cells (DEFCs) are a promising alternative to conventional energy sources, offering high energy density, environmental sustainability, and operational safety. Compared to methanol fuel cells, DEFCs exhibit lower toxicity and a more mature preparation process. Unlike hydrogen fuel cells, DEFCs provide superior storage and transport feasibility, as well as cost-effectiveness, significantly enhancing their commercial viability. However, the stable C–C bond in ethanol creates a high activation energy barrier, often resulting in incomplete electrooxidation. Current commercial platinum (Pt)- and palladium (Pd)-based catalysts demonstrate low C–C bond cleavage efficiency (

Effect Of Saccharin On Crystallization Behavior Of Electroless Cobalt Plating, Yu-Xin Luo, Jing-Jing Wang, Lu Wang, Zi-Yi Yan, Yi Ma, Xin Bo, Jing-Shuang Dang, Zeng-Lin Wang

Journal of Electrochemistry

In the process of electroless cobalt plating, the saccharin additive can significantly change the surface morphology, texture orientation, and conductivity of the cobalt coating layer. When the amount of saccharin was 3 mg·L^–1, the cobalt coating transformed from disordered large grains to a honeycomb structure, with a preferred orientation of (002) facet on hexagonal close-packed (HCP) cobalt crystals. The resistivity of the cobalt film decreased to 14.4 μΩ·cm, and further decreased to 10.7 μΩ·cm after the annealing treatment. When the concentration of saccharin was increased, the grain size was gradually refined and a “stone forest” structure was observed, …

3d-Printable Hydrogel With Rapid Ambient Self-Healing, Anna M. Petre

Research from the Berry Summer Thesis Institute, 2025

Inspired by nature, soft robots composed of compliant (“soft”) materials are well-suited for uncertain, dynamic tasks requiring safe interaction between a robot and its environment. Soft robots with the ability mend minor damage (e.g. perforations, tears) have been enabled by the rapid development of self-healing soft materials. Recently, one of these hydrogel materials (internally dubbed “BeckOHflex”) – made entirely from commercially available precursors – was developed with several appealing characteristics including rapid ambient self-healing, 3D printability on commercial machines, and competitive mechanical properties. However, the self-healing performance of BeckOHflex falls short of competitors that leverage custom-synthesized precursors. This project aims …