Force Controlled Manipulation of Biological Cells Using a Monolithic MEMS Based Nano-Micro Gripper

2012 ◽  
Author(s):  
Ali A. Abbasi ◽  
M. T. Ahmadian
Keyword(s):  
Liquid Medium ◽  
Force Control ◽  
Force Sensor ◽  
Rapid Response ◽  
Pid Controllers ◽  
Biological Cells ◽  
Matlab Software ◽  
Micro Gripper ◽  
The Future ◽  
Geometrical Dimensions

Nano-micro grippers are able to pick-transport-place the micro or nanometer–sized materials, such as manipulation of biological cells or DNA molecules in a liquid medium. This paper proposes a novel monolithic nano-micro gripper structure with two axis piezoresistive force sensor which its resolution is under nanoNewton. The results of the study have been obtained by the simulation of the proposed gripper structure in Matlab software. Motion of the gripper arm is produced by a voice coil actuator. The behavior of the cell has been derived using the assumptions in the literatures. Moreover, two simple PID controllers, one for control of the gripper motion and another for control of the force during manipulation of a biologic cell, have been implemented. Although the proposed gripper has not been fabricated, since the geometrical dimensions of the proposed gripper is the same as previously developed electrothermally actuated micro-nano gripper, the results of force control have been also compared with it. The simulated results with the very simple PID force controller which has a more rapid response than previously developed electrothermally actuated micro-nano gripper show that the designed gripper has the potential to be considered and fabricated for manipulation of biological cells in the future.

Design and Simulation of Space Deformable-Contact-Surface-Based End Effector

2013 ◽  
Vol 631-632 ◽  
pp. 1166-1171
Author(s):  
Huang Ran ◽  
Qian Xiang Zhou ◽  
Zhong Qi Liu
Keyword(s):  
Contact Surface ◽  
Force Control ◽  
Space Station ◽  
Matlab Software ◽  
End Effector ◽  
The Poor ◽  
The Future

It is common to use space arm for maintaining and assembling. The major technology problems to solve first are the deformability, the soft and tightening contact with the target. Use ER as the contactor of end effector which is learned from the space station end effector can overcome many problems, as the poor location precision and uncontainable attitude which is bring by the big space arm. The design of multi-DOF Deformable-Contact-Surface-Based shape adaptive end effector is introduced in this text. The simulation result by Matlab software proves the design not only can tight connect the target, but also can suppress vibration and meet the precise demand of location, precise force control and deformability. It can meet the multi-mission in the future.

Development of a Novel Micro-Gripper Integrating Tri-Axial Force Sensor

2007 ◽  
Author(s):  
Jiachou Wang ◽  
Weibin Rong ◽  
Lining Sun ◽  
Hui Xie ◽  
Wei Chen
Keyword(s):  
Axial Force ◽  
Crystalline Silicon ◽  
Force Sensor ◽  
Calibration Method ◽  
Deep Reactive Ion Etching ◽  
Micro Gripper ◽  
The Cross ◽  
Silicon Frame ◽  
High Level ◽  
Cross Structure

A novel micro gripper integrating tri-axial force sensor and two grades displacement amplifier is presented in this paper, which bases on the technology of Piezoresistive detection and use PZT as its micro driving component. The micro tri-axial force sensor is fabricated on a single-crystalline-silicon by the technology of MEMS and consists of a flexible cross-structure realized by deep reactive ion etching (DRIE). The arms of the cross-structure are connected to a silicon frame and to the central part of the cross-structure. After modeling the amplifier structure of micro gripper and the sensor, finite element method (FEM) is used to analyze the displacement of the micro gripper and the deformation of the cross-structure elastic cantilever. A calibration method of tri-axial sensor based on the technology of microscopic vision and the principle of bending deflection cantilever is proposed. The experimental verified that the sensor are high level of intrinsic decoupling of the signals from strain gauge, high resolutions in all three axes, high linearity and repeatability and simple produce of calculation. And also show the micro gripper is reasonable and practical. The sensor is capable of resolving forces up to 10mN with resolution of 2.4μN in x axis and y axis and up to 10mN with resolution of 4.2μN in z axis; the gripping displacement of the micro gripper is from 20μm to 300μm.

scholarly journals COVID-19 and the future of microfinance: evidence and insights from Pakistan

2020 ◽  
Vol 36 (Supplement_1) ◽  
pp. S138-S168 ◽  
Author(s):  
Kashif Malik ◽  
Muhammad Meki ◽  
Jonathan Morduch ◽  
Timothy Ogden ◽  
Simon Quinn ◽  
...  
Keyword(s):  
Low Income ◽  
Household Income ◽  
Commercial Banks ◽  
Policy Reform ◽  
Rapid Response ◽  
The Novel ◽  
Microfinance Institutions ◽  
The Future ◽  
Loan Officers ◽  
Novel Coronavirus

Abstract The COVID-19 pandemic threatens lives and livelihoods, and, with that, has created immediate challenges for institutions that serve affected communities. We focus on implications for local microfinance institutions in Pakistan, a country with a mature microfinance sector, serving a large number of households. The institutions serve populations poorly-served by traditional commercial banks, helping customers invest in microenterprises, save, and maintain liquidity. We report results from ‘rapid response’ phone surveys of about 1,000 microenterprise owners, a survey of about 200 microfinance loan officers, and interviews with regulators and senior representatives of microfinance institutions. We ran these surveys starting about a week after the country went into lockdown to prevent the spread of the novel coronavirus. We find that, on average, week-on-week sales and household income both fell by about 90 per cent. Households’ primary immediate concern in early April became how to secure food. As a result, 70 per cent of the sample of current microfinance borrowers reported that they could not repay their loans; loan officers anticipated a repayment rate of just 34 per cent in April 2020. We build from the results to argue that COVID-19 represents a crisis for microfinance in low-income communities. It is also a chance to consider the future of microfinance, and we suggest insights for policy reform.

scholarly journals An Adaptive Sliding-Mode Iterative Constant-force Control Method for Robotic Belt Grinding Based on a One-Dimensional Force Sensor

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1635 ◽  
Author(s):  
Tie Zhang ◽  
Ye Yu ◽  
Yanbiao Zou
Keyword(s):  
Force Control ◽  
Control Method ◽  
Sliding Mode ◽  
Force Sensor ◽  
Grinding Force ◽  
One Dimension ◽  
Constant Force ◽  
Belt Grinding ◽  
Robotic Belt Grinding ◽  
The Relationship

To improve the processing quality and efficiency of robotic belt grinding, an adaptive sliding-mode iterative constant-force control method for a 6-DOF robotic belt grinding platform is proposed based on a one-dimension force sensor. In the investigation, first, the relationship between the normal and the tangential forces of the grinding contact force is revealed, and a simplified grinding force mapping relationship is presented for the application to one-dimension force sensors. Next, the relationship between the deformation and the grinding depth during the grinding is discussed, and a deformation-based dynamic model describing robotic belt grinding is established. Then, aiming at an application scene of robot belt grinding, an adaptive iterative learning method is put forward, which is combined with sliding mode control to overcome the uncertainty of the grinding force and improve the stability of the control system. Finally, some experiments were carried out and the results show that, after ten times iterations, the grinding force fluctuation becomes less than 2N, the mean value, standard deviation and variance of the grinding force error’s absolute value all significantly decrease, and that the surface quality of the machined parts significantly improves. All these demonstrate that the proposed force control method is effective and that the proposed algorithm is fast in convergence and strong in adaptability.

A Force-Control Model for Edge-Deburring with Filamentary Brush

1999 ◽  
Vol 123 (3) ◽  
pp. 528-532 ◽  
Author(s):  
Lienjing Chen ◽  
Robert J. Stango ◽  
Vikram Cariapa
Keyword(s):  
Force Control ◽  
Material Removal ◽  
Complete Removal ◽  
Force Sensor ◽  
Control Model ◽  
Master Curves ◽  
Machining Performance ◽  
Unknown Variable ◽  
Machining Force ◽  
On Line

In this paper a force-control model is developed for edge deburring with filamentary brushes. The model is based upon experimentally obtained “master curves,” that is, material removal data that corresponds to the actual machining performance of the brush/workpart system during the incremental burr removal process. This information is used in conjunction with the on-line brush machining force to compute the brush feed rate that ensures complete removal of the edge burr. Computer simulated results are reported for the removal of an edge burr having unknown variable height. The results indicate that the present force-control model can provide a straight forward approach for computing brush feed rates that lead to complete removal of edge burrs, and suggests that implementation can be carried out using a force sensor and a simple control strategy.

Force Control of Robot Manipulator by Neural Network Model - Experiment and Evaluation of One-Degree-of-Freedom Manipulator -

1990 ◽  
Vol 2 (4) ◽  
pp. 273-281 ◽  
Author(s):  
Masatoshi Tokita ◽  
◽  
Toyokazu Mitsuoka ◽  
Toshio Fukuda ◽  
Takashi Kurihara ◽  
...  
Keyword(s):  
Neural Network ◽  
Network Model ◽  
Neural Network Model ◽  
Force Control ◽  
Pid Controller ◽  
Robot Manipulator ◽  
Force Sensor ◽  
Robotic Manipulator ◽  
The Neural Network ◽  
The Stability

In this paper, a force control of a robotic manipulator based on a neural network model is proposed with consideration of the dynamics of both the force sensor and objects. This proposed system consists of the standard PID controller, the gains of which are augmented and adjusted depending on objects through a process of learning. The authors proposed a similar method previously for the force control of the robotic manipulator with consideration of dynamics of objects, but without consideration of dynamics of the force sensor, showing only simulation results. This paper shows the similar structure of the controller via the neural network model applicable to the cases with consideration of both effects and demonstrates that the proposed method shows the better performance than the conventional PID type of controller, yielding to the wider range of applications, consequently. Therefore, this method can be applied to the force/compliance control problems. The effects of the number of neurons and hidden layers of the neural network model are also discussed through the simulation and experimental results as well as the stability of the control system.

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