A multi-fingered micromechanism for coordinated micro/nano manipulation,"

ABSTRACT Micromanipulators for coordinated manipulation of microand nano-scale objects are critical for advancing several emerging applications such as microassembly and manipulation of biological cells. Most of existing designs for micromanipulators accomplish either primarily microgripping or primarily micropositioning tasks, and relatively, only a very few are capable of accomplishing both microgripping and micropositioning, however, they are generally bulky. This paper presents conceptualization, design, fabrication and experimental characterization a novel micromanipulation station for coordinated planar manipulation combining both gripping and positioning of micro-and nano-scale objects. Conceptually, the micromanipulation station is comprised of multiple, independently actuated, fingers capable of coordinating with each other to accomplish the manipulation and assembly of micron-scale objects within a small workspace. A baseline design is accomplished through a systematic design optimization of each finger maximizing the workspace area of the manipulation station using the optimization toolbox in MATLAB. The device is micromachined on a SOI (silicon-oninsulator) wafer using the DRIE (Deep Reactive Ion Etching) process. The device prototype is experimentally characterized for the output displacement characteristics of each finger for known input displacements applied through manual probing. An excellent correlation between the experimental results and the theoretical results obtained through a finite element analysis in ANSYS software, which validates both the design and the fabrication of the proof-of-the-concept, is demonstrated

Design and realization of a microassembly workstation

With the miniaturization of products to the levels of micrometers and the recent developments in microsystem fabrication technologies, there is a great need for an assembly process for the formation of complex hybrid microsystems. Integration of microcomponents made up of different materials and manufactured using different micro fabrication techniques is still a primary challenge since some of the fundamental problems originating from the small size of parts to be manipulated, high precision necessity and specific problems of the microworld in that field are still not fully investigated. In this thesis, design and development of an open-architecture and reconfigurable microassembly workstation for efficient and reliable assembly of micromachined parts is presented. The workstation is designed to be used as a research tool for investigation of the problems in microassembly. The development of such a workstation includes the design of: (i) a manipulation system consisting of motion stages providing necessary travel range and precision for the realization of assembly tasks, (ii) a vision system to visualize the microworld and the determination of the position and orientation of micro components to be assembled, (iii) a robust control system and necessary fixtures for the end effectors that allow easy change of manipulation tools and make the system ready for the desired task. In addition tele-operated and semi-automated assembly concepts are implemented. The design is verified by implementing tasks in various ranges for micro-parts manipulation. The versatility of the workstation is demonstrated and high accuracy of positioning is shown

Advanced instrumented stamps for micro transfer printing and novel application areas

Transfer printing refers to a set of techniques for deterministic assembly of functional micro/nano scale devices into two and three dimensional spatial arrangements. It provides a versatile route for realizing multifunctional heterogeneously integrated systems such as flexible electronics, biocompatible sensing and therapeutic devices, transparent and curved optoelectronic systems etc. Micro-transfer printing is an automated process that implements deterministic micro scale assembly using a molded viscoelastic stamp typically made out of PDMS. The process relies upon the control of adhesion and fracture at the interfaces between the stamp and the devices being assembled to pick up and release them. A widely exploited strategy to achieve variable adhesion from the stamp is to use the rate dependent effects of the viscoelastic stamp material. It is a very versatile process and has been used in the realization of many novel heterogeneously integrated systems. The process has been implemented industrially to assemble ultra-high concentration photovoltaic panels. This body of work presents the development of new stamp technologies to address the challenges associated with increasing parallelism and shortcomings associated with fixed geometry stamps. Starting from the concept of an active composite material with distributed sensing, actuation and compliance tuning, new stamp architectures are developed. These novel stamps replace the compliance of a bulk PDMS stamp with active functional structures with tunable stiffness; without effecting the ability of the stamps to be used for transfer printing. The new stamp architecture enables active monitoring and control of the micro transfer printing process. Using instrumentation to sense deflections/forces at each post allows detection, measurement and compensation of misalignments between the stamp and donor/receiving substrates. Furthermore this information is used to detect pick up and printing errors at individual posts, allowing for error handling to increase process robustness. Moreover the ability to selectively actuate allows to engage/disengage individual posts. This enables new transfer printing modes such as collect and place. Finally results of pilot experiments conducted to test the feasibility of using micro transfer printing in novel application areas are presented

A multi-function, disposable, microfluidic module for mutation detection

Recognition of point mutations in a codon 12 of the K-ras gene, most frequently observed, is considered to be useful in the early diagnosis of several types of the human cancers. We have developed a multifunction, disposable, microfluidic module which detects low-abundant point mutations in human genomic DNA in modular architecture. Each functional component including a microfluidic PCR reactor, a passive diffusional micromixer reactor, and a microfluidic LDR reactor was separately designed and fabricated. Fluidic interconnects were also developed to make a fluidic passage between the functional components. Polycarbonate substrates were micro-molded, using hot embossing with micro-milled brass mold inserts to make all microfluidic components. Developed microassembly using passive alignment features, fabricated on all components, was used to assemble the functional components with the fluidic interconnects using an adhesive bonding technique. Thermal simulations were employed to ensure uniform thermal distributions in the microfluidic PCR and LDR reactors, to isolate the mixing junction in order to avoid heat–induced bubble formation in the passive micromixer reactor, and to have minimal thermal crosstalk due to the asymmetric thermal zones in the PCR and the LDR reactors. A control system was developed to control temperatures enabling thermal cycling in the microfluidic PCR and LDR reactor. LDR products were produced using the module within an hour with DNA sample, which had the ratio of 1:200. Total reaction time was about 67 minutes. By applying an enzyme as a purification of PCR products, a LDR analysis can be optimized and minimized to reduce the false positive signals and inconstant results generated by PCR products during the LDR. The purification system allowed us to successfully quantify the amount of mutant alleles in the genomic DNA. The high degree of accuracy in this module can also facilitate the detection of low-frequency point mutation occurred in other functional genes. This module, fabricated using replication technologies of polymers will be able to supply low cost, disposable detection tools for known disease-causing mutations and also expand to other PCR-based detection assays in diagnostic applications

Microfluidics and Nanofluidics Handbook

The Microfluidics and Nanofluidics Handbook: Two-Volume Set comprehensively captures the cross-disciplinary breadth of the fields of micro- and nanofluidics, which encompass the biological sciences, chemistry, physics and engineering applications. To fill the knowledge gap between engineering and the basic sciences, the editors pulled together key individuals, well known in their respective areas, to author chapters that help graduate students, scientists, and practicing engineers understand the overall area of microfluidics and nanofluidics. Topics covered include Finite Volume Method for Numerical Simulation Lattice Boltzmann Method and Its Applications in Microfluidics Microparticle and Nanoparticle Manipulation Methane Solubility Enhancement in Water Confined to Nanoscale Pores Volume Two: Fabrication, Implementation, and Applications focuses on topics related to experimental and numerical methods. It also covers fabrication and applications in a variety of areas, from aerospace to biological systems. Reflecting the inherent nature of microfluidics and nanofluidics, the book includes as much interdisciplinary knowledge as possible. It provides the fundamental science background for newcomers and advanced techniques and concepts for experienced researchers and professionals

Shape formation by self-disassembly in programmable matter systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 225-236).Programmable matter systems are composed of small, intelligent modules able to form a variety of macroscale objects with specific material properties in response to external commands or stimuli. While many programmable matter systems have been proposed in fiction, (Barbapapa, Changelings from Star Trek, the Terminator, and Transformers), and academia, a lack of suitable hardware and accompanying algorithms prevents their full realization. With this thesis research, we aim to create a system of miniature modules that can form arbitrary structures on demand. We develop autonomous 12mm cubic modules capable of bonding to, and communicating with, four of their immediate neighbors. These modules are among the smallest autonomous modular robots capable of sensing, communication, computation, and actuation. The modules employ unique electropermanent magnet connectors. The four connectors in each module enable the modules to communicate and share power with their nearest neighbors. These solid-state connectors are strong enough for a single inter-module connection to support the weight of 80 other modules. The connectors only consume power when switching on or off; they have no static power consumption. We implement a number of low-level communication and control algorithms which manage information transfer between neighboring modules. These algorithms ensure that messages are delivered reliably despite challenging conditions. They monitor the state of all communication links and are able to reroute messages around broken communication links to ensure that they reach their intended destinations. In order to accomplish our long-standing goal of programmatic shape formation, we also develop a suite of provably-correct distributed algorithms that allow complex shape formation. The distributed duplication algorithm that we present allows the system to duplicate any passive object that is submerged in a collection of programmable matter modules. The algorithm runs on the processors inside the modules and requires no external intervention. It requires 0(1) storage and O(n) inter-module messages per module, where n is the number of modules in the system. The algorithm can both magnify and produce multiple copies of the submerged object. A programmable matter system is a large network of autonomous processors, so these algorithms have applicability in a variety of routing, sensor network, and distributed computing applications. While our hardware system provides a 50-module test-bed for the algorithms, we show, by using a unique simulator, that the algorithms are capable of operating in much larger environments. Finally, we perform hundreds of experiments using both the simulator and hardware to show how the algorithms and hardware operate in practice.by Kyle William Gilpin.Ph.D