Microfluidic End Effector for Manufacturing of Nano Devices Uchechukwu C. Wejinya, Yantao Shen, Ning Xi, and Jiangbo Zhang Department of Electrical and Computer Engineering Michigan State University East Lansing, Michigan 48824, USA Email: {wejinyau, shenya, xin, zhangj15}@egr.msu.edu Abstract—In this paper, a new pneumatic end effector sys- tem for micro/nano fluidic handling, nanomanufacturing, and micro/nano manipulation is presented. The new micro pneumatic end-effector system consists of a DC micro-diaphragm pump and compressor, one region of flexible latex tube, a Polyvinylidene Fluoride (PVDF) sensor for in-situ measurement of micro force, and a micro steel tip. The micro steel tip of the new pneumatic end effector system has an internal diameter (ID) of 20μm used for handling nano entities such as carbon nanotubes, DNA, micro/nano particles as well as for microfluidic handling and droplet control. The DC micro-diaphragm pump is automatically controlled via a voltage driver interfaced with a computer in order to effectively and efficiently control suction force and pressure during microfluidic handling and droplet control in nano maufacturing. The new pneumatic end effector system with force sensing can significantly improve the success rate for handling/depositing micro/nano entities in the case of carbon nanotubes. The experimental results show the success rate of placing carbon nantubes between electrodes can reach close to 80%. Ultimately, the technology will provide a critical and major step towards the development of automated manufacturing process for batch assembly of micro devices, manufacturing of nano devices, microfluidic droplet control, and drug delivery. I. I NTRODUCTION Manufacturing processes which are capable of efficiently assembling nano devices have been studied and investigated by many researchers in the field. The assembling of nano devices involves the movement of nano parts to desired positions (and orientation) and the suitable forces have to be applied to these nano entities. Transporting and releasing the micro/nano entities precisely at the final position are also very critical. For macro object/parts, this problem is already solved by mechanical clamps using interaction forces or geometrically constraining grippers to hold and move the relatively heavy objects [4]. For small objects, sticking effect become more dominant. Compared to the adhesion and electrostatic forces, the weight and inertia of the entity can be neglected because they scale with the cube of the size [6][7]. Researchers have published extensively on micro tools for microassembly and micromanipulation, but rarely on mi- cro/nano tools for manufacturing of nano devices, and tools for microfluidic handling and transporting. For instance, in [8], Greitmann G., and Buser R. presented the microparts handling using micro tweezer. In [9], Miyazaki H. proposed the utilization of adhesion effects to provide the gripping force. In microbiology, very sensitive living cells are handled in a liquid environment using glass pipettes as presented in [11]. In addition, a vacuum tool and different active releasing mech- anisms are presented in [10]. In [3], the use of a pneumatic end effector system for microsuction, microfluidic handling, and manipulation is described. In designing micro/nano tools such as the gripper and end-effector, several major issues must be addressed. First, the operating target is fragile and can easily be destroyed. Therefore, the force acting on the targets must be meticu- lously controlled to effectively hold the target in a special environment due to sticking effect. Unlike macro objects that can be released by their self-gravitation, micro/nano entities need to be released by an active force. Therefore, force regulation and releasing methodologies for micro/nano tools must be considered. Second, the structure of the micro/nano tool must be simple and compact because of small operation workspace, and the micro/nano tool should be easily mounted on the micro/nano systems for microassembly, microfluidic handling and droplet control, manufacturing of nano devices, and micro/nano manipulation. In addition, micro/nano tools are very delicate, hence they have to be replaced frequently. As a result of this, efficiency of micro/nano operation is greatly reduced. Hence, micro/nano tools have to be simple and cheap. Micro fluidic transport and control is an important way for micro/nano handling, micro/nano manipulation, and mi- cro/nano assembly. Moving fluid through a device or channel, regardless of the application, requires a means of generat- ing flow. The right amount of the fluid must be precisely dropped/released at the desired location/place. Many methods have been presented in recent years including micromechan- ical, electrowetting, thermocapillary pumping, and electro- osmotic flow[13][15]. However, none of these methods have feedback. To realize the maximum benefit of micro/nano fluidic handling, it will be necessary to generate flow using tools that are integrated with sensing and feedback. In this paper, we focus on exploring and developing an effective and efficient solution for micro/nano fluidic handling, droplet control, micro/nano assembly, and micro/nano manip- ulation. That is, based on a new pneumatic vacuum/pressure mechanism, a micro end-effector, which is made from a micro steel tip with ID of 20μm, is designed. The micro end-effector (the micro steel tip) is connected with the inlet/outlet of an effective micro-diaphragm air pump through the tiny tube. Proceedings of the 2006 IEEE International Conference on Robotics and Automation Orlando, Florida - May 2006 0-7803-9505-0/06/$20.00 ©2006 IEEE 1384