More Like this

1. The crumpling transition of active tethered membranes

   https://doi.org/10.1039/D3SM00403A  

   Gandikota, M. C.; Cacciuto, A. (July 2023, Soft Matter)

   Active fluctuations of tethered membranes with no self-avoidance can be encapsulated by a simple rescaling of the background temperature. The self-avoiding membrane preserves its extended phase even in the presence of very large active fluctuations. 

   more » « less
2. Uniaxially crumpled graphene as a platform for guided myotube formation

   https://doi.org/10.1038/s41378-019-0098-6  

   Kim, Junghoon; Leem, Juyoung; Kim, Hong Nam; Kang, Pilgyu; Choi, Jonghyun; Haque, Md Farhadul; Kang, Daeshik; Nam, SungWoo (November 2019, Microsystems & Nanoengineering)

   Abstract Graphene, owing to its inherent chemical inertness, biocompatibility, and mechanical flexibility, has great potential in guiding cell behaviors such as adhesion and differentiation. However, due to the two-dimensional (2D) nature of graphene, the microfabrication of graphene into micro/nanoscale patterns has been widely adopted for guiding cellular assembly. In this study, we report crumpled graphene, i.e., monolithically defined graphene with a nanoscale wavy surface texture, as a tissue engineering platform that can efficiently promote aligned C2C12 mouse myoblast cell differentiation. We imparted out-of-plane, nanoscale crumpled morphologies to flat graphene via compressive strain-induced deformation. When C2C12 mouse myoblast cells were seeded on the uniaxially crumpled graphene, not only were the alignment and elongation promoted at a single-cell level but also the differentiation and maturation of myotubes were enhanced compared to that on flat graphene. These results demonstrate the utility of the crumpled graphene platform for tissue engineering and regenerative medicine for skeletal muscle tissues. 

   more » « less
3. Ultrasensitive Detection of Dopamine, IL‐6 and SARS‐CoV‐2 Proteins on Crumpled Graphene FET Biosensor

   https://doi.org/10.1002/admt.202100712  

   Hwang, Michael_Taeyoung; Park, Insu; Heiranian, Mohammad; Taqieddin, Amir; You, Seungyong; Faramarzi, Vahid; Pak, Angela_A; van_der_Zande, Arend_M; Aluru, Narayana_R; Bashir, Rashid (August 2021, Advanced Materials Technologies)

   Abstract Universal platforms for biomolecular analysis using label‐free sensing modalities can address important diagnostic challenges. Electrical field effect‐sensors are an important class of devices that can enable point‐of‐care sensing by probing the charge in the biological entities. Use of crumpled graphene for this application is especially promising. It is previously reported that the limit of detection (LoD) on electrical field effect‐based sensors using DNA molecules on the crumpled graphene FET (field‐effect transistor) platform. Here, the crumpled graphene FET‐based biosensing of important biomarkers including small molecules and proteins is reported. The performance of devices is systematically evaluated and optimized by studying the effect of the crumpling ratio on electrical double layer (EDL) formation and bandgap opening on the graphene. It is also shown that a small and electroneutral molecule dopamine can be captured by an aptamer and its conformation change induced electrical signal changes. Three kinds of proteins were captured with specific antibodies including interleukin‐6 (IL‐6) and two viral proteins. All tested biomarkers are detectable with the highest sensitivity reported on the electrical platform. Significantly, two COVID‐19 related proteins, nucleocapsid (N‐) and spike (S‐) proteins antigens are successfully detected with extremely low LoDs. This electrical antigen tests can contribute to the challenge of rapid, point‐of‐care diagnostics. 

   more » « less
4. Colloidal Photonic Crystal Strain Sensor Integrated with Deformable Graphene Phototransducer

   https://doi.org/10.1002/adfm.201902216  

   Snapp, Peter; Kang, Pilgyu; Leem, Juyoung; Nam, SungWoo (June 2019, Advanced Functional Materials)

   Abstract Flexible, architectured, photonic nanostructures such as colloidal photonic crystals (CPCs) can serve as colorimetric strain sensors, where external applied strain leads to a noticeable color change. However, CPCs' response to strain is difficult to quantify without the use of optical spectroscopy. Integration of flexible electrical readout of CPCs' color change is a challenge due to a lack of flexible/stretchable electrical transducers. This work details a colorimetric strain sensor with optoelectrical quantification based on an integrated system of CPCs over a crumpled graphene phototransducer, which optoelectrically quantifies CPCs, response to strain. The hybrid system enables direct visual perception of strain, while strain quantification via electrical measurement of the hybrid system outperforms that of crumpled graphene strain sensors by more than 100 times. The unique combination of a photonic sensing element with a deformable transducer will allow for the development of novel, electrically quantifiable colorimetric sensors with high sensitivity. 

   more » « less
5. A Pipe Dream Perspective on Totally Symmetric Self-Complementary Plane Partitions

   https://doi.org/10.1017/fms.2023.131  

   Huang, Daoji; Striker, Jessica (January 2024, Forum of Mathematics, Sigma)

   Abstract We characterize totally symmetric self-complementary plane partitions (TSSCPP) as bounded compatible sequences satisfying a Yamanouchi-like condition. As such, they are in bijection with certain pipe dreams. Using this characterization and the recent bijection of Gao–Huang between reduced pipe dreams and reduced bumpless pipe dreams, we give a bijection between alternating sign matrices and TSSCPP in the reduced, 1432-avoiding case. We also give a different bijection in the 1432- and 2143-avoiding case that preserves natural poset structures on the associated pipe dreams and bumpless pipe dreams. 

   more » « less