Yuto Shimoyama

Metre-long cell-laden microfibres exhibit tissue morphologies and functions

Artificial reconstruction of fibre-shaped cellular constructs could greatly contribute to tissue assembly in vitro. Here we show that, by using a microfluidic device with double-coaxial laminar flow, metre-long core-shell hydrogel microfibres encapsulating ECM proteins and differentiated cells or somatic stem cells can be fabricated, and that the microfibres reconstitute intrinsic morphologies and functions of living tissues. We also show that these functional fibres can be assembled, by weaving and reeling, into macroscopic cellular structures with various spatial patterns. Moreover, fibres encapsulating primary pancreatic islet cells and transplanted through a microcatheter into the subrenal capsular space of diabetic mice normalized blood glucose concentrations for about two weeks. These microfibres may find use as templates for the reconstruction of fibre-shaped functional tissues that mimic muscle fibres, blood vessels or nerve networks in vivo.

Backdrivability analysis of Electro-Hydrostatic Actuator and series dissipative actuation model

Although backdrivability is recognized as an important property of actuators, this term is often used without clear definition. In order to design mechanisms with advanced controllability, it is important to understand the fundamental mechanism of backdrivability. In this paper, we introduced idea of series elasticity and series dissipation of actuators. Based on this idea, total / output backdrivability and their fundamental properties are stated. EHA was shown to be series dissipative and it was confirmed from the model of the actuator. Utilizing the backdrivability of EHA, position based impedance control was implemented and evaluated. Application of this EHA in a robot hand is also reported.

Living cell fabric

This paper describes a centimeter-scale living cell fabric made of cell-containing core-shell hydrogel fibers, “cell fiber.” We improved core-shell fiber applicable to various types of cells, and precisely characterized their biofunctions and mechanical properties. Using these cell fibers, we demonstrate a centimeter-scale living cell fabric woven by our micro weaving machine. We believe that our weaving approach using cell fibers would be a powerful method for constructing large-scale 3D-patterned functional tissues.

Anthropomorphic robot hand with hydrostatic cluster actuator and detachable passive wire mechanism

Anthropomorphic robot hand has been an interest of researchers to investigate principle and to realize dexterous manipulation. However, designing such a hand had been a challenge due to their large degree of freedom and limited payload. Those challenges result in lack of actuator power, lack of durability, and poor maintainability. To overcome such issues of anthropomorphic robot hand, we proposed novel mechanism of robot hand with detachable passive wire mechanism and hydrostatic actuator cluster. In this paper, basic concept of the proposed hand, hydrostatic actuator and hand development, and basic experiments with the developed hand is explained.