Toshinori Fujie

Controlling the cellular microenvironment can be used to direct the cellular organization, thereby improving the function of synthetic tissues in biosensing, biorobotics, and regenerative medicine. In this study, we were inspired by the microstructure and biological properties of the extracellular matrix to develop freestanding ultrathin polymeric films (referred as “nanomembranes”) that were flexible, cell adhesive, and had a morphologically tailorable surface. The resulting nanomembranes were

A roll-to-roll process is reported for the preparation of free-standing conductive polymer nanosheets on large areas. Nanosheets are transferred in conformal contact with target surfaces (including skin) and act as unperceivable bio-electrodes.

It is anticipated that flexible wearable/implantable devices for biomedical applications will be established for the development of medical diagnostics and therapeutics. However, these devices need to be compatible with the physical and mechanical properties of the living body. In this minireview, we introduce free-standing polymer ultra-thin films (referred to as "polymer nanosheets"), for which a variety of polymers can be selected as building blocks (e.g., biodegradable polymers, conductive p

Investigation of the interactions between cells and material surfaces is important not only for the understanding of cell biology but also for the development of smart biomaterials. In this study, we investigated the substrate-related effects on the interaction between cell and polymeric ultrathin film (nanosheet) by modulating the mechanical properties of the nanosheet with a metal substrate or mesh. A freestanding polymeric nanosheet with tens-of-nanometers thickness composed of poly(L-lactic

To minimize the interference that skin-contact strain sensors cause natural skin deformation, physical conformability to the epidermal structure is critical. Here, we developed an ultrathin strain sensor made from poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) inkjet-printed on a polystyrene–polybutadiene–polystyrene (SBS) nanosheet. The sensor, whose total thickness and gauge factor were ∼1 µm and 0.73 ± 0.10, respectively, deeply conformed to the epidermal structure and s

Abstract Local delivery of physical energy, such as heat, is promising for the treatment of target lesions without the unintended distribution of heat to other normal tissue. However, the heating device must be equipped with an external power source or strong magnetic field to operate the device, and many of them are too large to be placed inside the body. In this regard, wireless, lightweight, flexible electronics can be used for the miniaturization of implantable devices. In this study, a flex

Abstract Paper electronics are expected to be a game‐changer in next‐generation flexible electronics that could replace conventional plastic electronics. Paper electronics are disposable and cost‐effective, two distinct advantages for the development of broadly accessible devices, but their poor performance has limited their practical implementation so far. Here, a high‐sensitivity, high‐performance, paper‐based, wearable ammonia sensor comprising composite poly(3,4‐ethylenedioxythiophene):poly(

Freestanding quasi-two-dimensional ultrathin films (e.g., 41 nm thick polymer nanosheets) were produced, on which stimuli-responsive 47 nm thick polymer brushes were constructed by atom transfer radical polymerization (ATRP) of poly(N-isopropylacrylamide). The resulting surfaces of the multilayered polysaccharide ultrathin films were evaluated by ellipsometry, IR imaging, in situ variable-temperature atomic force microscopy (AFM), and contact angle measurements. The morphological transformation

Abstract Surface electromyography (sEMG) is widely used to analyze human movements, including athletic performance. For baseball pitchers, a very precise movement is required to pitch the ball into the strike zone. The palm muscles appear to play a key role in this movement, and a real-time recording of sEMG from the palm muscle is useful in the analysis of motion during baseball pitching. However, the currently available devices with rigid and bulky electrodes (including connective wires) imped

This paper describes a biohybrid actuator consisting of a microgrooved thin film, powered by contractile, aligned skeletal muscle cells. The system was made of a thermoplastic elastomer [SBS, poly(styrene-<i>block</i>-butadiene-<i>block</i>-styrene)]. We prepared SBS thin films with different thicknesses (0.5-11.7 μm) and Young's moduli (46.7-68.6 MPa) to vary their flexural rigidity. The microgrooves on the SBS thin film resembled the microstructure of the extracellular matrix of muscle and fac

Most polymers solidify below a glass transition temperature (Tg), which is important for the fabrication of polymeric materials. The glass transition dynamics (GTD) of polymers alters their physical properties and therefore the range of applications suitable for the particular materials. In this regard, most GTD studies were oriented to the thermodynamics of amorphous polymer systems, while little studies were known for semicrystalline polymers. Here, we focus on the glassy and crystalline prope