Stem Cell Microarrays for Assessing Growth Factor Signaling in Engineered Glycan Microenvironments

The incorporation of extracellular matrix (ECM) elements such as adhesion motifs, growth factors and signaling molecules provides unique functionalities to biomaterials in regenerative medicine. However, an often overlooked component of native microenvironments are extracellular glycans, which are key players in mediating biological processes in signaling and development. Here, we describe a cellular microarray which presents well-defined glycan structures in a synthetic hydrogel ECM microenvironment to colonies of embryonic stem cells (ESCs) in a spaitally adressable format. In conjunction with synthetic glycan microenvironments, this new platform enables screening well-defined desulfated heparin glycans in the extracellular space by linking protein-glycan interactions directly with mitogen activated protein kinase (MAPK) signaling events leading to differentiation. The cellular array technique provides a potent tool to rapidly optimize the glycan ECM and providing guiding principles for incorporation of functional glycan elements into biomaterial design.

Vibration Absorption in a Nonlinear Metamaterial Beam Incorporating Shape Memory Alloys

Locally resonant metamaterials are capable of demonstrating low-frequency vibration absorption due to the formation of stop-bands. In this work, the multi-mode vibration absorption capability of an adaptive nonlinear metamaterial beam is investigated. The metamaterial beam is idealized as a hinged-hinged finite Euler-Bernoulli beam with a von-Kármán geometric type nonlinearity that is attached to a distributed cellular array of shape memory alloy (SMA) spring–mass resonators. Numerical studies are performed to evaluate the effects of dissipation and change in elastic modulus due to material phase change of SMA pseudoelasticity on the dynamic response of the beam. Using a modal analysis approach, stop-bands are generated at the first three nonlinear frequencies of the beam. The frequency response demonstrates a hardening behavior at a temperature significantly higher than the austenite finish temperature while conversely demonstrating a softening behavior at a temperature slightly above the austenite finish temperature.

Design of a Bio-Inspired Embryonic Cellular Array Based on Bus Structure

There are some shortcomings, such as huge hardware resource consumption, functional differentiation is difficult and limited fault detection coverage, when embryonic cellular array (ECA) is used to design large-scale circuit. In this paper, the structure characteristics and communication method of multicellular organism are analyzed briefly, and a new bio-inspired ECA based on bus structure (BECA) is proposed, besides that the corresponding self-repairing strategy is designed. First, the functional decomposition has been applied in BECA, which uses bus structure to realize internal communication. BECA consists of bus and electronic tissues (ET), which can be used to realize large-scale circuit. C17 circuit in ISCAS85 circuit library is chosen as experiment subject, and experiment simulation results indicate that BECA based on bus structure is suitable for large-scale circuit, and the faults occurred in ET can be repaired effectively. In order to research BECA from the mathematical point of view, the reliability evaluation model of BECA is established, which is based on [Formula: see text]-out-of-[Formula: see text] system reliability model. In addition, the hardware resource consumption model of BECA is established by analyzing the number of metal oxide semiconductor (MOS) transistors that ECA consumed. Based on BECA reliability and hardware resource consumption evaluation model, comparative experiment is studied, and the results indicate that the proposed ECA can improve the reliability of circuit and reduce hardware resource consumption effectively. Therefore, the BECA presented will play an important role in designing large-scale digital circuit with self-repairing ability.