Rolled-up magnetic microdrillers: Towards remotely controlled minimally invasive surgery

Self-folded magnetic microtools with sharp ends are directed at enabling drilling and related incision operations of tissues, ex vivo, in a fluid with a viscosity similar to that of blood. These microtools change their rotation from a horizontal to a vertical one when they are immersed into a rotational magnetic field. Novel self-assembly paradigms with magnetic materials can enable the creation of remotely controlled and mass-produced tools for potential applications in minimally invasive surgery

Cell viability and noninvasive in vivo MRI tracking of 3D cell encapsulating self-assembled microcontainers.

Several molecular therapies require the implantation of cells that secrete biotherapeutic molecules and imaging the location and microenvironment of the cellular implant to ascertain its function. We demonstrate noninvasive in vivo magnetic resonance imaging (MRI) of self-assembled microcontainers that are capable of cell encapsulation. Negative contrast was obtained to discern the microcontainer with MRI; positive contrast was obtained in the complete absence of background signal. MRI on a clinical scanner highlights the translational nature of this research. The microcontainers were loaded with cells that were dispersed in an extracellular matrix, and implanted both subcutaneously and in human tumor xenografts in SCID mice. MRI was performed on the implants, and microcontainers retrieved postimplantation showed cell viability both within and proximal to the implant. The microcontainers are characterized by their small size, three dimensionality, controlled porosity, ease of parallel fabrication, chemical and mechanical stability, and noninvasive traceability in vivo

Self-assembled circuit patterns

Abstract. Self-assembly is a process in which basic units aggregate under attractive forces to form larger compound structures. Recent theoretical work has shown that pseudo-crystalline self-assembly can be algorithmic, in the sense that complex logic can be programmed into the growth process [26]. This theoretical work builds on the theory of twodimensional tilings [8], using rigid square tiles called Wang tiles [24] for the basic units of self-assembly, and leads to Turing-universal models such as the Tile Assembly Model [28]. Using the Tile Assembly Model, we show how algorithmic self-assembly can be exploited for fabrication tasks such as constructing the patterns that define certain digital circuits, including demultiplexers, RAM arrays, pseudowavelet transforms, and Hadamard transforms. Since DNA self-assembly appears to be promising for implementing the arbitrary Wang tiles [30, 13] needed for programming in the Tile Assembly Model, algorithmic self-assembly methods such as those presented in this paper may eventually become a viable method of arranging molecular electronic components [18], such as carbon nanotubes [10, 1], into molecular-scale circuits.

Basic problems in self-assembling robots and a case study of segregation on Tribolon Platform

It has been a quite while since people realized that self-assembly technique may be a strong method to manufacture 3D micro products. In this contribution, we investigate some major concerns about realizing such a small sized robot. First we introduce the concept of self-assembly and introduce examples both from nature and artificial products. Followed by the main problems in self-assembly which can be seen in various scales, we classify them into four groups - (A) assembly constraint issues, (B) stochastic motion issues, (C) interactions on physical property issues, and (D) engineering issues. Then we show a segregation effect with our developed platform as an example of self-organizing behavior achieved in a distributed manner