## vWFNg

### Tv

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̓Iɂ͎Ɉȉ̃gsbNɂČ{Ă܂D

• nChQɂ}CN\
• HwIAv[ɂ鐶̑gD\z
• IEÓIȎȑgDۂ̍č\zƂ̍Hwp
• @\ޗɂfoCX
• }CÑfoCX/}CNEimXP[̕

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### nChQɂ}CN\

nChQ͐܂ލqlbg[NŏoĂĈɗDޗƂĒڂĂ܂DߔÑ}CNHZp̐iɂC┼݂̂̂Ȃ炸C|}[nChQȂǂ̃\tg}eA}CNXP[ł̐Hł悤ɂȂĂ܂DɂCnChQޗ̐Vȋ@\≞p\oƂ҂ł܂D{ł́CnChQ̃}CNHyу}CN\\zɊւ@_̍\zƁC̋@\\tgANG[^hbNfo[VXeiDDSjւ̉pWJsĂ܂D

Spring-shaped stimuli-responsive hydrogel actuator with large deformation

"This study describes a novel microfluidics-based method for compressive/expanding actuation of stimuli-responsive hydrogel microsprings with large deformations. A continuous flow of mixed alginate and poly(N-isopropylacrylamide-co-acrylic acid) pre-gel solution can spontaneously form a hydrogel microspring with a wide range of gradient pitches via buoyancy force. This technique enables fabrication of hydrogel microsprings using only simple capillaries and syringe pumps. The resulting microsprings can be patterned via laminar flow inside the capillary, which can contribute to large deformation. Single-layered hydrogel microsprings shrunk isotropically while maintaining the shape of the spring. Compressing stimuli-responsive microsprings can be done by patterning the shrinking part of the spring. Here, the degree of compression in the double-layered spring depends on the initial pitch. Furthermore, large axial expansion of microsprings can be achieved by shrinking part of a microspring. Our large compression/expansion stimuli-responsive hydrogel microsprings have immense potential to be applied in various microengineering products including soft actuators, chemical sensors, and medical applications." [Ref] Yoshida et.al., Sensors and Actuators B: Chemical, 2018. [link]

Stimuli-responsive hydrogel microfibers with controlled anisotropic shrinkage and cross-sectional geometries

"Stimuli-responsive microfibers are fabricated by extruding mixed solutions of poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM-AAc) and sodium alginate (Na-alginate) using a microfluidic spinning system. The fabricated microfibers shrink and swell with temperature and/or pH. By controlling the extruded laminar flow, microfibers capable of anisotropic shrinkage are fabricated. Cross-sectional microscale geometries of microfibers, including double layering and hollowness, are successfully controlled by patterning the laminar flow during microfiber formation, resulting in hydrogels capable of folding/unfolding motions and fluid pumping. In addition, macroscopic 3D-bundle structures are assembled with these microfibers. We believe that our microfibers can be applied to various applications such as soft actuators, soft robots, and micropumps." [Ref] Nakajima, et.al., Soft Matter, 2017. [link]

### HwIAv[ɂ鐶̑gD\z

X̐ĝ͗lXȊ튯CgDɂč\Ă܂D琶̓̊튯gD̍\זExł݂ƁC푽lȍזEĎOIɔz񂵂\Ă邱ƂmĂ܂D̐̓iin vivoj̍\lHIɐ̊Oiin vitrojŖ͋[邱Ƃł΁Ĉ̎튯gD̋@\X̎ōč\z\łƍl܂D{ł́CזEHwI_ōޗƂđC𒁏OgDƂČ{gAbvI\@̊mƁC̑gDɂ鐶@\̔ڎw܂D̋ZpɂCĐÂa𖾂̂߂̐lHgDf̑noCѐVĴ߂̃c[ƂĉpڎwČWJĂ܂D

Fiber-shaped artificial tissue with microvascular networks for bottom-up tissue reconstruction

"This paper describes a fiber-shaped microscale tissue with blood vessel networks. We co-cultured Hep-G2(Human hepatic epithelial cell line) and HUVEC(human umbilical endothelial cell) in a collagen/alginate core-shell hydrogel microfiber fabricated by using a microfluidic device. By culturing these microfibers, we found that blood vessel networks were constructed in the hepatic tissue. In addition, by arranging the fiber-shaped tissues to construct macroscale tissue assembly, we confirmed the connection of blood vessel networks between the assembled fiber-shaped tissues. We believe that our fiber-shaped tissue with blood vessel networks could contribute to the long-term maintenance of macroscale tissues in the tissue engineering field." [Ref] Sato et al., MEMS 2017, 2017.

Differentiation of 3D]shape]controlled mouse neural stem cell to neural tissues in closed agarose microchambers

"This paper describes three]dimensional (3D) tissue shape control of mouse neural stem cell (mNSC) micro tissues by using closed agarose microchambers for effective differentiation induction of neurons in vitro. Our agarose microchambers, made by micromolding, can be sealed with an agarose sheet to form the mNSC tissues along the shape of microchambers. We constructed lane]shaped mNSC tissues with different width (60-210 m) and thickness (25-95 m) dimensions and induced differentiation to neurons with differentiation medium. We found that in thick tissues (thickness: >60 m), distribution of differentiated neurons was not uniform, whereas in thin tissues (thickness: 30 m), differentiated neurons were uniformly distributed with high differentiation efficiency. Our system to construct in vitro 3D neural tissues having uniformly distributed neurons at high differentiation ratio, could become an effective tool for drug screening using 3D neural tissues and 3D mNSC tissues under differentiation induction." [Ref] Matsushiro, et.al., Biotechnology and Bioengineering, 2018. [link]

Double-layer collagen microtube for perfusable heterogeneous culture

"We present a double-layer collagen microtube device for in vitro perfusable multilayered 3D cell culture. Thicknesses of the collagen layers in the microtube can flexibly designed, and heterogeneous types of cells can be co-cultured in each collagen layer or surfaces. Moreover, while our collagen tube is directly attached to silicone tubes, the collagen microtube can be easily connected to an external pump system for perfusion culture. We believe that our device could help easy fabrication of various tissue models mimicking in vivo, especially blood vessel models or vascularized skin models, and contribute to the development of pharmacokinetic testing platforms and regenerative medicine." [Ref] Itai, et.al., MicroTAS 2017, 2017.

### IEÓIȎȑgDۂ̍č\zƂ̍Hwp

REAɐۂȂǂɌɂ݂铮IŕGȎȑgDۂ̗́AȊwɂ钆SIȃgsbN̈łB̂悤Ȍۂ́AGlM[̗Eoɂێ铮IȌۂłA܂qXP[}NȐE܂ŊKwIɑݍpAȃVXełƉ߂Ă܂B̂悤ȃVXelHIɍč\in肾jƂ́AȊw҂ɂƂĂHw҂ɂƂĂɂ̖ڕẄƌ܂B{ł́A}CNXP[̉HZpx[XɂāÂ悤ȓIȎȑgDVXe̎Iȍ\zڎwƓɁAHwIȉpWJ̒Ts܂B

Dynamic transformation of self-assembled structures using anisotropic magnetized hydrogel microparticles

"This paper describes a system through which the self-assembly of anisotropic hydrogel microparticles is achieved, which also enables dynamic transformation of the assembled structures. Using a centrifuge-based microfluidic device, anisotropic hydrogel microparticles encapsulating superparamagnetic materials on one side are fabricated, which respond to a magnetic field. We successfully achieve dynamic assembly using these hydrogel microparticles and realize three different self-assembled structures (single and double pearl chain structures, and close-packed structures), which can be transformed to other structures dynamically via tuning of the precessional magnetic field. We believe that the developed system has potential application as an effective platform for a dynamic cell manipulation and cultivation system, in biomimetic autonomous microrobot organization, and that it can facilitate further understanding of the self-organization and complex systems observed in nature." [Ref] Yoshida et al., Journal of Applied Physics, 2016. [link]

### @\ޗɂfoCX

@\ޗ͖̌ڊo܂AXVȑfނ܂Ă܂D̑fނ𓝍AX험p\ȃfoCX邽߂ɂ́A}CNXP[ł̉HZpMEMSiMicro-Electro-Mechanical SystemsjЗ͂𔭊ƉX͍lĂ܂D{ł́ARChimJ[{ޗC@\qƂĂDNAȂǂ𓝍C̃VXeƂċ@\@_̊JʂĐVfoCX̒Ăs܂D

Graphene-based inline pressure sensor integrated with microfluidic elastic tube

"We propose an inline pressure sensor composed of a polydimethylsiloxane (PDMS) microfluidic tube integrated with graphene sheets. The PDMS tube was fabricated through molding, and a multilayered graphene sheet was transferred on the surface of the PDMS tube. The pressure inside the tube was monitored using the changes in the electrical resistance of the transferred graphene. The proposed pressure sensor could be suitable for precise pressure measurement for a small amount of fluid in microfluidic systems including organ-on-a-chip devices." [Ref] Inoue et al., Journal of Micromechanics and Microengineering, 2018. [link]

Multiple structural color hydrogel array integrated with microfluidic chip for biochemical sensor

"This paper describes multiple structural color hydrogel array integrated with a two-layered microfluidic chip. The microfluidic chip can sense multiple physical/chemical targets (ex. concentration of chemicals and temperature) at the same time simply by eye-visible color changes of the arrayed stimuli-responsive structural color hydrogels in the top chambers. Sample solution was introduced in the bottom channel and react to the arrayed hydrogel via sandwiched porous membrane. We evaluated our device by measuring ethanol/water concentration and temperature, and confirmed the visible color changes of our sensor without any external equipment. We believe that our sensing device could be applied to a biochemical sensor or microanalytical chip for environmental monitoring sensor and wearable healthcare devices." [Ref] Niibe et al., Transducers 2017, 2017.

### DNAɂvOꂽȑgD

DNA-programmed micropatterning of living cells

"Synthetic DNA strands can be attached to the plasma membrane of living cells to equip them with artificial adhesion “receptors” that bind to complementary strands extending from material surfaces. This approach is compatible with a wide range of cell types, offers excellent capture efficiency, and can potentially be used to create complex multicellular arrangements through the use of multiple capture sequences.The utility of this approach is demonstrated through the observation of patterned cells as they communicate by diffusion-based paracrine signaling." [Ref] Onoe et al., Langmuir, 2012. [link]

### }CÑfoCX/}CNEimXP[̕

}CNimXP[ɂgbv_E̋@BHZp͗lXɐ[Ă܂D̒ŁCtHg\OtB[ɂ锼̉HZp@Bvf\z}CN}VEMEMSZpiMicromachine, Micro-Electro-Mechanical-Systemsj́Aŏ̓VR̉Hn܂܂\NŐxƑΏۂƂޗLCqXP[foCXZpȂ߂̒jIȋZpɂȂ܂D{ł́Ĉ߂MEMS/NEMS/}CÑfoCX̌s܂Dɑ̃XP[̍ޗVXeƂ̑݊֌WӎČWJƋɁC̉ߒł鏔̕ۂɂĎg݂܂D

Liquid-filled flexible micro suction-controller array for enhanced robotic object manipulation

"With the intent to enhance robotic manipulation, this paper describes a novel liquid-filled flexible micro suction-controller array (MISCA) for humanoid robotic hands that can hold curved or grooved surface objects. The proposed MISCA comprises 49 suction units arrayed in a 10 mm ~ 10 mm area of flexible polydimethylsiloxane sheet. Each 1 mm diameter suction unit generates suction force independently. An incompressible working fluid (ethylene glycol) is injected or drained through microchannels in the MISCA using a syringe pump to control the suction force. In experiments, the proposed MISCA effectively generated suction forces of 0.96-1.54 N on flat surfaces, 0.43-0.63 N on cylindrical surfaces, and 0.60-0.83 N on spherical surfaces. In addition, the proposed MISCA was demonstrated to successfully manipulate a 75 g flat object (a watch), a 1-g grooved object (a yen coin), and a curved object (a tablet) using suction control." [Ref] Nishita et al., Journal of Microelectromechanical Systems, 2017. [link]

Micropatterning of multiple photonic colloidal crystal gels for flexible structural color films

"We herein report the micropatterning of flexible multiple photonic colloidal crystal gels (PCCGs) using single-layered microchannels. These patterned PCCGs exhibit structural colors that can be tuned by adjustment of the diameter and concentration of the colloidal particles in precursor solutions of N-isopropylacrylamide (NIPAM) or polyethylene glycol diacrylate (PEGDA). The precursor solutions containing dispersed colloidal particles were selectively injected into single-layered microchannels where they polymerized rapidly. The shape, density, and height of the patterned PCCG pixels were determined by the microchannels, which in turn determined the optical properties of the PCCG arrays. Furthermore, the preparation of three different types of PCCGs exhibiting three different structural colors at a high pixel density was demonstrated successfully using the single-layered polydimethylsiloxane (PDMS) microchannels. Finally, the optical reflective properties and the mechanical flexibility of the patterned multiple PCCG arrays were evaluated. We expect that our method for the preparation of such patterned PCCG arrays will contribute to the development of flexible optical devices." [Ref] Suzuki et al., Langmuir, 2017. [link]

Microfluidic-based flexible reflective multicolor display

"This paper describes a microfluidic-based flexible reflective display constructed using dyed water droplets and air gaps as pixel elements. Our display is composed of a flexible polydimethylsiloxane sheet with a connected pixel-patterned microchannel. Several types of dyed water droplets and air gaps are sequentially introduced to the microchannel through a suction process to display a multicolor image. The displayed image is stable and can be retained without an energy supply. To ensure that images are displayed correctly, the geometric parameters of the dot pixel design and minimum differential pressure necessary to drive the water droplets are evaluated. As a demonstration, we successfully display three-color dot-matrix reflective images and bitmap characters in the microchannel. Our proposed method can be applied to energy-less and color-changeable displays for use in future daily-life accessories, such as bags, shoes, and clothes, and can change the surface color and pattern of these accessories." [Ref] Kobayashi et al., Microsystems & Nanoengineeringvolume, 2018. [link]