More Like this

1. Scalable nanomanufacturing of chalcogenide inks: a case study on thermoelectric V–VI nanoplates

   https://doi.org/10.1039/d1ta05858d  

   Zeng, Minxiang ; Xie, Hongyao ; Saeidi-Javash, Mortaza ; Tanvir, A.N.M. ; Du, Yipu ; Chen, Jiahao ; Kanatzidis, Mercouri G. ; Zhang, Yanliang ( October 2021 , Journal of Materials Chemistry A)

   null (Ed.)

   Solution-processed semiconducting main-group chalcogenides (MMCs) have attracted increasing research interest for next-generation device technologies owing to their unique nanostructures and superior properties. To achieve the full potential of MMCs, the development of highly universal, scalable, and sustainable synthesis and processing methods of chalcogenide particles is thus becoming progressively more important. Here we studied scalable factors for the synthesis of two-dimensional (2D) V–VI chalcogenide nanoplates (M 2 Q 3  : M = Sb, Bi; Q = Se, Te) and systematically investigated their colloidal behaviour and chemical stability. Based on a solvent engineering technique, we demonstrated scale-up syntheses of MMCs up to a 900% increase of batch size compared with conventional hydrazine-based gram-level syntheses, and such a scalable approach is highly applicable to various binary and ternary MMCs. Furthermore, we studied the stability of printable chalcogenide nanoparticle inks with several formulation factors including solvents, additives, and pH values, resulting in inks with high chemical stability (>4 months). As a proof of concept, we applied our solution-processed chalcogenide particles to multiple additive manufacturing methods, confirming the high printability and processability of MMC inks. The ability to combine the top-down designing freedom of additive manufacturing with bottom-up scalable synthesis of chalcogenide particles promises great opportunities for large-scale design and manufacturing of chalcogenide-based functional devices for broad application. 

   more » « less
2. 3D Printing of Solution‐Processable 2D Nanoplates and 1D Nanorods for Flexible Thermoelectrics with Ultrahigh Power Factor at Low‐Medium Temperatures

   https://doi.org/10.1002/advs.201901788  

   Dun, Chaochao ; Kuang, Wenzheng ; Kempf, Nicholas ; Saeidi‐Javash, Mortaza ; Singh, David J. ; Zhang, Yanliang ( October 2019 , Advanced Science)

   Solution‐processable semiconducting 2D nanoplates and 1D nanorods are attractive building blocks for diverse technologies, including thermoelectrics, optoelectronics, and electronics. However, transforming colloidal nanoparticles into high‐performance and flexible devices remains a challenge. For example, flexible films prepared by solution‐processed semiconducting nanocrystals are typically plagued by poor thermoelectric and electrical transport properties. Here, a highly scalable 3D conformal additive printing approach to directly convert solution‐processed 2D nanoplates and 1D nanorods into high‐performing flexible devices is reported. The flexible films printed using Sb₂Te₃nanoplates and subsequently sintered at 400 °C demonstrate exceptional thermoelectric power factor of 1.5 mW m⁻¹K⁻²over a wide temperature range (350–550 K). By synergistically combining Sb₂Te₃2D nanoplates with Te 1D nanorods, the power factor of the flexible film reaches an unprecedented maximum value of 2.2 mW m⁻¹K⁻²at 500 K, which is significantly higher than the best reported values for p‐type flexible thermoelectric films. A fully printed flexible generator device exhibits a competitive electrical power density of 7.65 mW cm⁻²with a reasonably small temperature difference of 60 K. The versatile printing method for directly transforming nanoscale building blocks into functional devices paves the way for developing not only flexible energy harvesters but also a broad range of flexible/wearable electronics and sensors.

    

   more » « less
3. Additive Nanomanufacturing of Multifunctional Materials and Patterned Structures: A Novel Laser‐Based Dry Printing Process

   https://doi.org/10.1002/admt.202001260  

   Ahmadi, Zabihollah ; Lee, Seungjong ; Unocic, Raymond R. ; Shamsaei, Nima ; Mahjouri‐Samani, Masoud ( March 2021 , Advanced Materials Technologies)

   Direct printing of functional materials, structures, and devices on various platforms such as flexible to rigid substrates is of interest for applications ranging from electronics to energy and sensing to biomedical devices. Current additive manufacturing (AM) and printing processes are either limited by the available sources of functional materials or require to be in the form of precisely designed inks. Here, a novel laser‐based additive nanomanufacturing (ANM) system capable of in situ and on‐demand generations of nanoparticles that can serve as nanoscale building blocks for real‐time sintering and dry printing a variety of multifunctional materials and patterns at atmospheric pressure and room temperature is reported. The ability to print different functional materials on various rigid and flexible platforms is shown. This nonequilibrium process involves pulsed laser ablation of targets and in situ formation of pure amorphous nanoparticles’ stream that are guided through a nozzle onto the surface of the substrate, where they are sintered/crystallized in real‐time. Further, the process–structure relationship of the printed materials from nanoscale to microscale is shown. This new ANM concept opens up an opportunity for printing advanced functional materials and devices on rigid and flexible substrates that can be employed both on the earth and in space.

    

   more » « less
4. Colloidal Nanosurfactants for 3D Conformal Printing of 2D van der Waals Materials

   https://doi.org/10.1002/adma.202003081  

   Zeng, Minxiang ; Kuang, Wenzheng ; Khan, Irfan ; Huang, Dali ; Du, Yipu ; Saeidi‐Javash, Mortaza ; Zhang, Lecheng ; Cheng, Zhengdong ; Hoffman, Anthony J. ; Zhang, Yanliang ( August 2020 , Advanced Materials)

   Printing techniques using nanomaterials have emerged as a versatile tool for fast prototyping and potentially large‐scale manufacturing of functional devices. Surfactants play a significant role in many printing processes due to their ability to reduce interfacial tension between ink solvents and nanoparticles and thus improve ink colloidal stability. Here, a colloidal graphene quantum dot (GQD)‐based nanosurfactant is reported to stabilize various types of 2D materials in aqueous inks. In particular, a graphene ink with superior colloidal stability is demonstrated by GQD nanosurfactants via the π–π stacking interaction, leading to the printing of multiple high‐resolution patterns on various substrates using a single printing pass. It is found that nanosurfactants can significantly improve the mechanical stability of the printed graphene films compared with those of conventional molecular surfactant, as evidenced by 100 taping, 100 scratching, and 1000 bending cycles. Additionally, the printed composite film exhibits improved photoconductance using UV light with 400 nm wavelength, arising from excitation across the nanosurfactant bandgap. Taking advantage of the 3D conformal aerosol jet printing technique, a series of UV sensors of heterogeneous structures are directly printed on 2D flat and 3D spherical substrates, demonstrating the potential of manufacturing geometrically versatile devices based on nanosurfactant inks.

    

   more » « less
5. Printing Conductive Nanomaterials for Flexible and Stretchable Electronics: A Review of Materials, Processes, and Applications

   https://doi.org/10.1002/admt.201800546  

   Huang, Qijin ; Zhu, Yong ( January 2019 , Advanced Materials Technologies)

   Printed electronics is attracting a great deal of attention in both research and commercialization as it enables fabrication of large‐scale, low‐cost electronic devices on a variety of substrates. Printed electronics plays a critical role in facilitating widespread flexible electronics and more recently stretchable electronics. Conductive nanomaterials, such as metal nanoparticles and nanowires, carbon nanotubes, and graphene, are promising building blocks for printed electronics. Nanomaterial‐based printing technologies, formulation of printable inks, post‐printing treatment, and integration of functional devices have progressed substantially in the recent years. This review summarizes basic principles and recent development of common printing technologies, formulations of printable inks based on conductive nanomaterials, deposition of conductive inks via different printing techniques, and performance enhancement by using various sintering methods. While this review places emphasis on conductive nanomaterials, the printing techniques and ink formulations can be applied to other materials such as semiconducting and insulating nanomaterials. Moreover, some applications of printed flexible and stretchable electronic devices are reviewed to illustrate their potential. Finally, the future challenges and prospects for printing conductive nanomaterials are discussed.

    

   more » « less