@article{hosseini_rahmanian_pirzada_frick_krissanaprasit_khan_labean_2022, title={DNA aerogels and DNA-wrapped CNT aerogels for neuromorphic applications}, volume={16}, ISSN={["2590-0064"]}, url={https://doi.org/10.1016/j.mtbio.2022.100440}, DOI={10.1016/j.mtbio.2022.100440}, abstractNote={Nucleic acids are programmable materials that can self-assemble into defined or stochastic three-dimensional network architectures. Various attributes of self-assembled, cross-linked Deoxyribonucleic acid (DNA) hydrogels have recently been investigated, including their mechanical properties and potential biomedical functions. Herein, for the first time, we describe the successful construction of pure DNA aerogels and DNA-wrapped carbon nanotube (CNT) composite (DNA-CNT) aerogels via a single-step freeze-drying of the respective hydrogels. These aerogels reveal highly porous and randomly branched structures with low density. The electrical properties of pure DNA aerogel mimic that of a simple capacitor; in contrast, the DNA-CNT aerogel displays a fascinating resistive switching behavior in response to an applied bias voltage sweep reminiscent of a volatile memristor. We believe these novel aerogels can serve as a platform for developing complex biomimetic devices for a wide range of applications, including real-time computation, neuromorphic computing, biochemical sensing, and biodegradable functional implants. More importantly, insight obtained here on self-assembling DNA to create aerogels will pave the way to construct novel aerogel-based material platforms from DNA coated or wrapped functional entities.}, journal={MATERIALS TODAY BIO}, author={Hosseini, Mahshid and Rahmanian, Vahid and Pirzada, Tahira and Frick, Nikolay and Krissanaprasit, Abhichart and Khan, Saad A. and LaBean, Thomas H.}, year={2022}, month={Dec} } @article{frick_hosseini_guilbaud_gao_labean_2022, title={Modeling and characterization of stochastic resistive switching in single Ag2S nanowires}, volume={12}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-022-09893-4}, abstractNote={Chalcogenide resistive switches (RS), such as Ag2S, change resistance due to the growth of metallic filaments between electrodes along the electric field gradient. Therefore, they are candidates for neuromorphic and volatile memory applications. This work analyzed the RS of individual Ag2S nanowires (NWs) and extended the basic RS model to reproduce experimental observations. The work models resistivity of the device as a percolation of the conductive filaments. It also addressed continuous fluctuations of the resistivity with a stochastic change in volume fractions of the filaments in the device. As a result, these fluctuations cause unpredictable patterns in current-voltage characteristics and include a spontaneous change in resistance of the device during the linear sweep that conventional memristor models with constant resistivity cannot represent. The parameters of the presented stochastic model of a single Ag2S NW were fitted to the experimental data and reproduced key features of RS in the physical devices. Moreover, the model suggested a non-core shell structure of the Ag2S NWs. The outcome of this work is aimed to aid in simulating large self-assembled memristive networks and help to extend existing RS models.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Frick, Nikolay and Hosseini, Mahshid and Guilbaud, Damien and Gao, Ming and LaBean, Thomas H.}, year={2022}, month={Apr} } @article{hosseini_frick_guilbaud_gao_labean_2022, title={Resistive switching of two-dimensional Ag2S nanowire networks for neuromorphic applications}, volume={40}, ISSN={["2166-2754"]}, DOI={10.1116/6.0001867}, abstractNote={Randomly assembled networks of nanowires (NWs) can display complex memristive behaviors and are promising candidates for use as memory and computing elements in neuromorphic applications due to device fault tolerance and ease of fabrication. This study investigated resistive switching (RS) in two-dimensional, self-assembled silver sulfide (Ag 2 S) NW networks first experimentally and then theoretically using a previously reported stochastic RS model. The simulated switching behavior in these networks showed good correlation with experimental results. We also demonstrated fault-tolerance of a small NW network that retained RS property despite being severely damaged. Finally, we investigated information entropy in NW networks and showed unusual dynamics during switching as a result of self-organization of the memristive elements. The results of this work provide insights toward physical implementation of randomly assembled RS NW networks for reservoir and neuromorphic computing research.}, number={4}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Hosseini, Mahshid and Frick, Nikolay and Guilbaud, Damien and Gao, Ming and LaBean, Thomas H.}, year={2022}, month={Jul} } @article{malhotra_hosseini_zaferani_hall_vashaee_2020, title={Enhancement of Diffusion, Densification and Solid-State Reactions in Dielectric Materials Due to Interfacial Interaction of Microwave Radiation: Theory and Experiment}, volume={12}, ISSN={["1944-8252"]}, DOI={10.1021/acsami.0c09719}, abstractNote={A detailed theoretical model and experimental study are presented that formulate and prove the existence of a robust ponderomotive force (PMF) near the interfaces in a granular dielectric material under microwave radiation. The model calculations show that the net direction of the PMF is pore angle-dependent. For most of the pore angles, the net force is towards the interface creating a mass transport that fills the interfacial pores and facilitates densification. For small ranges of angles, near 180o and 360o, PMF drives the ions in the reverse direction and depletes the pores. However, the net force for such ranges of angles is small. The PMF also enhances the diffusion of the mobile ionic species and, consequently, accelerates the solid-state reaction by increasing the collision probability. The proof-of-concept experiments show that a mixture of elemental powders can diffuse, react, and form dense materials when radiated by the microwave in just a few minutes. Such characteristics, together with field-induced decrystallization, offer a novel and simple approach for the synthesis of nanostructured compounds, which can have practical implications in ceramic technologies and thermoelectric materials.}, number={45}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Malhotra, Abhishek and Hosseini, Mahshid and Zaferani, Sadeq Hooshmand and Hall, Michael and Vashaee, Daryoosh}, year={2020}, month={Nov}, pages={50941–50952} } @misc{nozariasbmarz_collins_dsouza_polash_hosseini_hyland_liu_malhotra_ortiz_mohaddes_et al._2020, title={Review of wearable thermoelectric energy harvesting: From body temperature to electronic systems}, volume={258}, ISSN={["1872-9118"]}, url={https://publons.com/publon/30967440/}, DOI={10.1016/j.apenergy.2019.114069}, abstractNote={Abstract Global demand for battery-free metrics and health monitoring devices has urged leading research agencies and their subordinate centers to set human energy harvesting and self-powered wearable technologies as one of their primary research objectives. After an overview of wearables market trends, different active and passive methods of body energy harvesting for powering low-consumption electronic devices are introduced, and challenges of device fabrication are discussed. The discussion continues with the primary emphasis on thermoelectric generators for body heat harvesting. The physiological aspects of the human body involved in heat generation are elaborated. System requirements and the influence of different parameters on the performance of thermoelectric generators are studied at the material, device, and system levels. Finally, the advancements in the development of rigid and flexible thermoelectric generators for wearable and textile integration are presented.}, journal={APPLIED ENERGY}, author={Nozariasbmarz, Amin and Collins, Henry and Dsouza, Kelvin and Polash, Mobarak Hossain and Hosseini, Mahshid and Hyland, Melissa and Liu, Jie and Malhotra, Abhishek and Ortiz, Francisco Matos and Mohaddes, Farzad and et al.}, year={2020}, month={Jan} } @article{nozariasbmarz_hosseini_vashaee_2019, title={Interfacial ponderomotive force in solids leads to field induced dissolution of materials and formation of non-equilibrium nanocomposites}, volume={179}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2019.08.017}, abstractNote={We report that microwave radiation can decompose continuous solid-solution materials into their constituent phases – a process that is thermodynamically unfavorable at equilibrium. A detailed analysis of the interaction of the electromagnetic wave with the material showed that a strong ponderomotive force preferentially separates the constituent phases via an enhanced mass transport process amplified particularly near the interfaces. The proof of concept experiments showed that the material, whether it is a solid-solution of two elements, e.g. (Si 1-x Ge x ), or two compounds, e.g. (Bi 2 Te 3 ) 1-x (Sb 2 Te 3 ) x , decomposes into the constituent phases when radiated by a polarized microwave field. The dissolution happens in the bulk of the material and even below the melting point. The degree of decomposition can be controlled by radiation parameters to produce structures composed of gradient phases of the solid-solution. This offers a novel and facile method for synthesizing gradient composite and complex structures for application in thermoelectricity as well as fabrication of core-shell structures for catalysts and biomedical applications.}, journal={ACTA MATERIALIA}, author={Nozariasbmarz, Amin and Hosseini, Mahshid and Vashaee, Daryoosh}, year={2019}, month={Oct}, pages={85–92} }