Graphene/Glycerin Solution-Based Multifunctional Stretchable Strain Sensor with Ultra-High Stretchability, Stability, and Sensitivity.

Highly stretchable, flexible, and sensitive strain sensors have promising applications in motion detection-especially multifunctional strain sensors that can detect stretching, bending, compression and twisting. Herein, this study presents a graphene and glycerol solution-based multifunctional sensor with ultra-high stretchability and sensitivity. Owing to the self-lubrication and fluidity of the graphene-glycerol solution, the strain sensors display super stretchability up to 1000%, a maximum gauge factor up to 45.13, and excellent durability for over 10,000 cycles. In addition, the sensor can also rapidly respond to small strains (1%, 5%, 10%) and different stretching rates (12.5%/s, 25%/s, 50%/s, and 100%/s). More impressively, the sensors can measure up to 50 kPa pressure and 180° twisting without any damage. Furthermore, the strain sensors demonstrate their applicability in scenarios involving motion detection, such as that for finger bending, wrist rotating, touching, and drinking water.

SEM imaging of the stimulatory response of RAW264.7 cells against Porphyromonas gingivalis using a simple technique employing new conductive materials.

In the medical biology, it is essential to understand not only biological morphology but also the interaction between biological materials and agents. To study these, electron microscopy (EM) is often utilized. However, sample preparation techniques for EM require a high level of skill and a considerable time. Here, we conducted EM using a simple technique employing a conductive liquid, BEL-1, and compared the results with another simple technique employing an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4 ]). BEL-1 was used for sample pretreatment, and the morphologies of the mouse RAW 264.7 cell line, Porphyromonas gingivalis, and the RAW 264.7 cell line were stimulated via co-incubation with P. gingivalis and observed using field emission scanning EM (FE-SEM). In the present study, the inflammation-induced system of P. gingivalis was successfully established. FE-SEM results revealed the fine morphology of the RAW 264.7 cell line and P. gingivalis and confirmed a morphological change in the RAW 264.7 cell line caused by P. gingivalis stimulation. Using the developed sample preparation technique employing BEL-1, high-contrast and high-resolution observations of deformable biological materials were conducted without any difficulty or the necessity for complicated technique. This morphological information and the developed techniques can contribute to reveal the interaction between biological materials and agents and thereby accelerate drug formulation and disease treatment. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1280-1285, 2018.