Recent Research

A Photothermal Solar Tunnel Radiator (PSTR) is designed and developed by employing multiple transparent photothermal glass panels (Fig. 1). The primary objective is to pioneer a transformative approach to achieve energy-neutral building heating utilities, exemplified by a lab-scale "Photothermal Solar Box" (PSB) exclusively heated with TPGP under natural sunlight (Fig. 2). The PSTR presents a novel paradigm for sustainable energy, enabling direct solar energy capture through transparent glass substrates with photothermal coatings. The high transparency of Fe3O4@Cu2-xS coated glass substrates enhance efficient solar harvesting and photothermal energy generation within the Photothermal Solar Box. The system demonstrates an impressive thermal energy output, reaching up to 9.1x105 joules with 8 photothermal panels in parallel. Even under colder conditions (ambient temperature: -10 °C), with accelerated heat loss, the interior temperatures of the PSB with partial thermal insulation achieve a commendable 35 °C, showcasing effective photothermal heating in cold weather. These findings indicate the system's resilience and efficiency in harnessing solar energy under diverse conditions, including partial cloudy weather. The initiative contributes to broader sustainability goals by providing a scalable and practical alternative to traditional solar heating methods, aligning with the global mission for a cleaner, greener future.

A photothermal solar tunnel via multiple transparent Fe3O4@Cu2-xS thin films for heating utility application, Anudeep Katepalli, Yuxin Wang, Jou Lin, Anton Harfmann, Mathias Bonmarin, Solar Energy 271 (2024) 112444

John Krupczak, Donglu Shi, https://doi.org/10.1016/j.solener.2024.112444

Research supported by National Science Foundation CMMI-1953009, CMMI-1635089 and the Michelman Green, Clean and Sustainable Technology Research Innovation Program (F103484). 

By introducing a novel photothermal radiator that effectively harnesses diffused light through plasmonic Fe₃O₄@Cu2-xS nanoparticles, we seek to offer a sustainable solution for maintaining comfortable indoor temperatures without heavy reliance on traditional solar sources. Our approach involves the use of UV and IR lights to photothermally activate transparent Fe₃O₄@Cu2-xS thin films, showcasing a proactive strategy to optimize energy capture even in low-light scenarios such as cloudy days or nighttime hours (Fig. 1). This innovative technology carries immense potential for energy-neutral buildings, paving the way to reduce dependence on external energy grids and promoting a more sustainable future for indoor heating and comfort control. The developed photothermal radiator incorporates multiple transparent thin films infused with plasmonic Fe₃O₄@Cu2-xS nanoparticles, known for their robust UV and IR absorptions driven by Localized Surface Plasmon Resonance (LSPR). Through the application of UV and IR lights, these thin films efficiently convert incident photons into thermal energy (Fig. 2). Our experiments within a specially constructed Diffused Light Photothermal Box (DLPB), designed to simulate indoor environments, demonstrate the system's capability to raise temperatures above 50°C effectively.

Photothermal Utility Heating with Diffused Indoor Light via Multiple Transparent Fe3O4@Cu2xS Thin Films, Anudeep Katepalli, Neshwanth Kumar Tene, Yuxin Wang, Anton Harfmann, Mathias Bonmarin, John Krupczak, and Donglu Shi, Energy Technology, https://doi.org/10.1002/ente.202400703 (2024)

Research supported by National Science Foundation CMMI-1953009, CMMI-1635089 and the Michelman Green, Clean and Sustainable Technology Research Innovation Program (F103484). 

Among major energy conversion methods, photovoltaic (PV) solar cells have been the most popular and widely employed for a variety of applications. Although a PV solar panel has been shown as one of the most efficient green energy sources, its 2D surface solar light harvesting has reached great limitations as it requires large surface areas. There is, therefore, an increasing need to seek solar harvest in a three-dimensional fashion for enhanced energy density. In addition to a conventional 2D solar panel in the x-y area, we extend another dimension of solar harvesting in the z-axis through multiple CdTe solar panels arranged in parallel (Fig. 1). The high transparency allows sunlight to partially penetrate multiple solar panels, resulting in significantly increased solar harvesting surface area in a 3D fashion (Fig. 2). The advantages of the 3D multi-panel solar harvesting system include: i) enlarged solar light collecting surface area, therefore increased energy density, ii) the total output power from multiple panels can exceed that of the single panel, and iii) significantly reduced surface area needed for densely populated cities. With five CdTe solar panels of different transparencies in parallel, the multilayer system can produce collective output power 233% higher than that of the single solar panel under the same surface area when arranged in descending (i.e., PV panel with the highest transparency on top and lowest at bottom).  The PCE of the multi-panel system has also increased 233% in descending order indicating the viability of 3D solar harvesting. The multi-panel system will dimensionally transform solar harvesting from 2D to 3D for more efficient energy generation.

Solar harvesting through multiple semi-transparent cadmium telluride solar panels for collective energy generation, Anudeep Katepalli, Yuxin Wang, Donglu Shi, Solar Energy 264 (2023) 112047

Research supported by National Science Foundation CMMI-1953009, CMMI-1635089 and the Michelman Green, Clean and Sustainable Technology Research Innovation Program (F103484). 

A fundamental challenge in energy sustainability is efficient utilization of solar source towards energy-neutral systems. The current solar cell technologies have been most widely employed to achieve this goal, but limited to a single-layer 2D surface. To harvest solar light more efficiently, we have developed a multilayer system capable of harvesting solar light in a cuboid (5 x 5 x 15 cm³) through transparent photothermal thin films of iron oxide and a porphyrin compound (Fig. 1). Analogous to a multilayer capacitor, an array of transparent, spectral selective, photothermal thin films allows white light to penetrate them, not only collecting photon energy in a 3D space, but generating sufficient heat on each layer with significantly increased total surface area. The multilayer system extends another dimensionality in solar harvesting and paves a new path to energy generation for the energy-neutral system. In this fashion, thermal energy is generated via a multilayer photothermal system that functions as an efficient solar collector, energy converter and generator with high energy density. The energy densities inside the cuboid with both types of thin films have reached 1.48×10⁸ J/m³ via multilayers. The solar-activated thermal energy generator in a cuboid can produce heat without any power supply and reach a maximum temperature of 76.1 °C (Fig. 1). With a constant incoming white light (0.4W⋅ cm^-2), the thermal energy generated can be amplified twelvefold and increased from 5074.3 J (one layer) to 55, 465.8 J (ten layers) for the Fe3O4@Cu2-xS system, and increased from 3826.3 J (one layer) to 56, 143.9 J (ten layers) for chlorophyllin system, both have more than tenfold of increase. The solar photothermal efficiency (η) of the system is greater than 60 % with 10 layers of transparent films. These experimental results demonstrate a concept of “Thermal Generator” that will show promise in major energy-applications.

Source of Support: NSF CMMI-1635089 and CMMI-1953009

Related Publications: Solar harvesting through multilayer spectral selective iron oxide and porphyrin transparent thin films for photothermal energy generation, Mengyao Lyu, Jou Lin, John Krupczak, and Donglu Shi, Advanced Sustainable Systems, 2021.

A building skin has been conventionally considered as a weather-resistive barrier without any active functions. This project revolutionizes this traditional concept by structurally transforming the building skin to a versatile energy network capable of harvesting sunlight according to the seasonal changes for energy efficiency. In this new concept, a building skin is considered multifunctionally active for natural energy harvesting, conversion, and utilization. The glass-based high-rise building skins provide ideal transparent substrates for device architecture of energy harvesting nanoscale thin films. A nanostructured thin film on building skin is engineered to offer two major functions: photovoltaic or photothermal, switched alternatively depending on the seasonal needs. In summer, the photovoltaic effect of the coating consumes most of the solar infrared therefore less cooling is required. In winter, the slight increase in skin temperature by the photothermal coating can lead to lowered heat loss from room interior.  The goal of this research is to develop a multifunctional building skin capable of efficient solar harvesting for different energy outputs, be it thermal or electric via dual-modality, spectral selective, seasonably altered. Principally, both photothermal and photovoltaic films share the same optical characteristics: strong UV/NIR absorptions with high visible transmittance, the only difference is the output energy form. The outcomes of the research activities will address the national needs in energy sustainability by entirely transforming the landscape of architectural engineering, civic system design, and energy saving strategy.

Source of Support: NSF CMMI – 1953009 ECI-Engineering for Civil Infrastructure
Related Publications: Spectral selective and photothermal nano structured thin films for energy efficient windows

Jou Lin and Donglu Shi, Photothermal and photovoltaic properties of transparent thin films of porphyrin compounds for energy applications. Applied Physics Reviews, 8, 011302 (2021)

In 3D solar still, sunlight can pass through several transparent panels coated with the photothermal thin films, and generate sufficient heat on each layer for water evaporation. Controlled by valves, seawater is flowing on the surfaces of these panels in a shallow depth and constantly heated by the photothermal coatings on the substrates, resulting in high evaporation rates. Due to multilayers, the total surface area exposed to sunlight is significantly increased, depending upon the total number and size of the multilayers designed. The 3D Solar Still system is entirely relying on natural resources: solar light and seawater, no electrical power is required, therefore environmentally green. The 3D Solar Still can be scaled up to mega sizes in large fields, capable of producing huge quantity of desalinated water for drinking and agricultural irrigation.

Related Publications: Solar Desalination via Multilayers of Transparent Photothermal Fe3O4@Cu2–xS Thin Films,

Mengyao Lyu, Jou Lin, Donglu Shi, Energy Technology, 18 September 2021

A new concept of thermal insulation, namely, optical thermal insulation is achieved without any intervention medium such as air or argon, as often used in the conventional glazing technologies. Various transparent, spectral-selective photothermal thin films, based on iron oxide and porphyrin compounds, not only result in sufficient solar light harvest in a wide spectrum, but also allow for efficient conversion of solar light to heat in the non-visible region. If a spectral-selective thin film is applied on a window surface, the skin surface temperature can be increased from 25 °C to > 50 °C via the photothermal effect. This will in turn effectively reduce the thermal energy loss from the interior, based on the so-called optical thermal insulation. Both Fe₃O₄@Cu_2-xS and the porphyrin compounds are found to exhibit strong UV and NIR absorptions, but high visible transmittance. Upon coating the inner surface of the window glass with a photothermal film, under solar irradiation, the window is heated to reduce the temperature difference (see figure), between the single-pane and room interior. The photothermally heated window surface will effectively lower heat transfer through the building skin, therefore achieving the goal of energy saving without double- or triple- glazing. These photothermal materials are abundant in nature and environmentally friendly. The fundamental photothermal mechanisms are identified for both iron oxide and porphyrin compounds in terms of their electronic structures. The novel concept paves a new way for thermal insulation without insulating materials. The engineering implications show great promise in both energy and materials savings for sustainability.

Source of Support: NSF CMMI-1635089
Related Publications:

• Optical thermal insulation via the photothermal effects of Fe3O4 and Fe3O4@Cu2−xS thin films for energy-efficient single-pane windows
• Light angle dependence of photothermal properties in oxide and porphyrin thin films for energy-efficient window applications

A common microstructural feature of the soft magnetic materials is the ferromagnetic nano-crystallites (~10-20 nm) embedded in an amorphous matrix, whose average size is considerably smaller than the correlation length, L, resulting in a unique combination of large magnetization, high permeability, and an extremely low coercive field. The magnetic softness has been explained by the random anisotropy model which predicts that the local magneto-crystalline anisotropy, K, will have a strong dependence of the gran size, D: K ~ (D/L). As shown by several studies, the correlation lengths of Fe-based alloys are between 40-120 nm for grain size well below 20 nm. In the amorphous state, the structure crystalline features are absent (it is structurally highly isotropic), therefore the magneto-crystalline anisotropy will become negligible, resulting in extremely soft magnetic properties. This project is focused on developing the soft magnetic alloys to provide a highly power dense magnetic core with low losses. The research includes rapid solidification, crystallization, and fine powder processing for high-temperature soft magnetic materials. By developing ferromagnetic nano-crystallites (~10 nm) embedded in an amorphous matrix, which are considerably shorter than the correlation length, a soft magnetic material is obtained with superb magnetic properties and extremely low cohesive fields.

Source of Support: Ohio Department of Higher Education (CWRU RES511312 sub ODHE)
Related Publications:

• Nanocrystallites via Direct Melt Spinning of Fe77Ni5.5Co5.5Zr7B4Cu for Enhanced Magnetic Softness
• Processing of Soft Magnetic Fine Powders Directly From As-Spun Partial Crystalline Fe77Ni5.5Co5.5Zr7B4Cu Ribbon via Ball Mill Without Devitrification

A key property for high-frequency inductive applications is the magnetic softness, ideally characterized by complete reversibility of the hysteresis curve. Magnetic softness of alloys depends on the dimensional ratio of grain size to the correlation length. The random anisotropy model predicts the optimum magnetic softness if the crystallite size is well below the correlation length. Based on this theory, a common strategy in processing is to obtain extremely fine nanoscale grains via rapidly solidified alloys, followed by a controlled vacuum anneal. As is well-known, this conventional approach requires two demanding experimental conditions: 1) an extremely high quench rate, > 105 K/s, and 2) a high vacuum anneal near 600 °C to avoid oxidation. Furthermore, the completely amorphous ribbon is extremely elastic and mechanically strong and is not easily made into the fine powder form for net-shaping and three-dimensional printing of the soft magnets. Therefore, annealing to induce crystallization is a necessary step before using any conventional powdering techniques, such as ball milling. In this study, we report a new processing strategy of making Fe77Ni5.5Co5.5Zr7B4Cu powders directly from the as-spun ribbons without any crystallization annealing step. This is achieved by melt-spinning of the alloy at a relatively low quenching rate, resulting in partially crystalline ribbons that deform plastically, a behavior that is in sharp contrast to its amorphous counterpart (Fig. 1). Magnetization measurements show extremely low coercive field (Fig. 2).

Processing of Soft Magnetic Fine Powders Directly From As-Spun Partial Crystalline Fe77Ni5.5Co5.5Zr7B4Cu Ribbon via Ball Mill Without Devitrification Som V. Thomas, Matthew A. Willard, Anthony Martone, Michael J. Heben, Virgil Solomon, Aaron Welton, Punit Boolchand, Rodney C. Ewing, Chenxu Wang, Sergey L Bud’ko, Jie Song, and Donglu Shi, IEEE TRANSACTIONS ON MAGNETICS, VOL. 56, NO. 6, JUNE 2020

Research supported by Ohio Federal Research Network with Award No. RSC16038/WSARC-1077-400

COVID-19 is known to be transmitted through respiratory droplets that originate from coughs and sneezes of an infected person. Infectious droplets can land on surfaces surrounding an infected individual, including bedding, floors, walls, and objects that may subsequently be contacted by uninfected individuals. Methods to prevent such transmission have been recommended by CDC, including the use of hand sanitizer, alcohol, and a diluted solution of sodium hypochlorite. In practice, most of the disinfectants are in liquid or gel forms that may apply directly on skins and hard surfaces. Soft surfaces of clothing, packaging, and everyday mail are, however, not easily disinfected by applying WET disinfectants. It is therefore critical to develop a DRY treatment that can be easily and frequently applied on these everyday items. This research investigates the effect of cold atmospheric plasma on virus disinfection. Plasma is matter in the form of ions and electrons with significant energies, thus viewed as reactive species that can bombard any cell surfaces resulting in significant structural damages. A gas (air, nitrogen, argon, oxygen) can be electrified and charged with freely moving electrons in both the negative and positive state. These plasma radicals can interrupt a biological system at different levels depending upon the power applied and treatment duration to: induce amino acid oxidation; reduce enzyme activity, damage DNA and RNA, and break cell membrane. These effects will all contribute to viral transfection, however to different degrees. By studying the transfection efficiency, we will be able to determine the activity of the virus that has been treated by plasma under given conditions. This research is carried out in collaboration with Dr. Paul Spearman, Director of Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center.

Source of Support: NSF 2029268 IIP - PFI-Partnerships for Innovation
Related Publications:

• Effects of plasma surface modification on interfacial behaviors and mechanical properties of carbon nanotube-Al2O3 nanocomposites
• Plasma deposition of Ultrathin polymer films on carbon nanotubes

Endothelial cell dysfunction occurs in a variety of acute and chronic pulmonary diseases including pulmonary hypertension, viral and bacterial pneumonia, bronchopulmonary dysplasia, and congenital lung diseases such as alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV). To correct endothelial dysfunction, there is a critical need for the development of nanoparticle systems that can deliver drugs and nucleic acids to endothelial cells with high efficiency and precision. While several nanoparticle delivery systems targeting endothelial cells have been recently developed, none of them are specific to lung endothelial cells without targeting other organs in the body. In the present study, we successfully solved this problem by developing non-toxic poly(β-amino) ester (PBAE) nanoparticles with specific structure design and fluorinated modification for high efficiency and specific delivery of nucleic acids to the pulmonary endothelial cells (Fig. 1) . After intravenous administration, the PBAE nanoparticles could deliver non-integrating DNA plasmids to lung microvascular endothelial cells but not to other lung cell types. IVIS whole body imaging and flow cytometry demonstrated that DNA plasmid were functional in the lung endothelial cells but not in endothelial cells of other organs. Fluorination of PBAE was required for lung endothelial cell-specific targeting. Hematologic analysis and liver and kidney metabolic panels demonstrated the lack of toxicity in experimental mice. Thus, fluorinated PBAE nanoparticles can be an ideal vehicle for gene therapy targeting lung microvascular endothelium in pulmonary vascular disorders.

Fluorinated amphiphilic Poly(β-Amino ester) nanoparticle for highly efficient and specific delivery of nucleic acids to the Lung capillary endothelium, Zicheng Deng, Wen Gao, Fatemeh Kohram, Enhong Li, Tanya V. Kalin, Donglu Shi, Vladimir V. Kalinichenko

Bioactive Materials, 31 (2024) 1–17, https://doi.org/10.1016/j.bioactmat.2023.07.022

Sensitive detection of circulating tumor cells (CTCs) from clinical peripheral blood sample can serve as an effective tool in cancer diagnosis and prognosis through liquid biopsy. Cancer cells that shed from the primary tumor and enter the circulation are responsible for proximal intravasation events leading to metastases within the vasculature. CTCs are extremely rare in blood, probably only one for everyone billion normal cells. However, reliable targeting strategy, sensitive isolation, enumeration and molecular profiling of the CTCs can be used as one of the independent biomarkers for cancer prognosis and risk screening. Challenges for CTCs isolation typically involve accuracy, completeness, and sensitivity, which cannot be easily dealt with by employing a single biomarker. A few of commercially available CTC enumeration and separation technologies such as CellSearch, CelSee, Parsortix, all face critical challenges due to the rarity and heterogeneity of the CTCs. Newly-developed CTCs isolation technique based on surface charge feature of tumor cells derived from its glycolysis hallmark and lactate secretion shows good potential as a competent supplementary. Besides the technical progresses in CTCs targeting and isolation, the significance of clinical cues from CTC analysis has been recognizing by physiologists and doctors, which boosts the rapid development of the integrate microfluidic devices for combination of CTC isolation, identification and in-situ analysis. In this review, we present the current progresses in liquid biopsy with new CTCs targeting, isolation and identification technologies based on magnetic beads and microfluidic devices and discuss their technical viabilities and clinical perspectives.

Circulating tumor cell isolation for cancer diagnosis and prognosis Zicheng Deng, Shengming Wu, Yilong Wang, and Donglu Shi eBioMedicine 2022;83: 104237 (2022)

https://doi.org/10.1016/j.ebiom.2022.104237

There is a critical need for the development of effective strategies for small molecule or non-viral gene therapy for tailored treatment at the molecular level. Nanotechnology provides a promising avenue for tailored treatment of these diseases, overcoming the struggles of current regimens. In collaboration with Dr. Vladimir V. Kalinichenko from Cincinnati Children’s Hospital Research Foundation, we jointly develop novel formulations of cationic based, non-viral nanoparticles that efficiently target the pulmonary microvascular network for the delivery of nucleic acids. Nanoparticles are created by functionalizing low molecular weight polyethylenimine (PEI) with biological fatty acids and carboxylate terminated poly(ethylene glycol) (PEG) through a one-pot EDC/NHS reaction. These polyplexes provide a powerful basis for selective delivery of nucleic acids for therapeutic treatments.

Fig. C) Immunofluorescent images of lung microvasculature and large vessels for (−)- and (+)-coated polyplexes. (C-b,b′) nanoparticle only channel for (C-a,a′) the respective field of view. (C-c,c′) Nanoparticle only channel for (+) polyplexes showing (C-c) high affinity within microvasculature and (c′) reduced targeting within large vessels. IF of (−) and (+) polyplexes are taken from different samples imaged under the same acquisition parameters.

Source of Support: Cincinnati Children’s Hospital
Related Publications:

• Highly Efficient In Vivo Targeting of the Pulmonary Endothelium Using Novel Modifications of Polyethylenimine: An Importance of Charge
• Nanoparticle Delivery of Proangiogenic Transcription Factors into the Neonatal Circulation Inhibits Alveolar Simplification Caused by Hyperoxia