Andi Sudjana Putra

Design, Modeling, and Control of Piezoelectric Actuators for Intracytoplasmic Sperm Injection

The modeling and control of two piezoelectric actuators (PAs), with an objective application towards intracytoplasmic sperm injection (ICSI), is addressed in this paper. The PAs are used to realizing the fast and precise movements of an injector so as to penetrate an oocyte (egg cell) with precision and without causing a large deformation. Two specific PA designs are considered for this application: linear reciprocating and partially rotating. General models are presented for the purpose of control system design for both designs. To address the nonlinearities and uncertainties of the actuators, as represented in the model, an adaptive controller is proposed to yield robust control performance. Application results are presented and discussed in this paper. Successful penetration of the zona pellucida (cell membrane) of the oocyte to the ICSI problem has been achieved with both designs and the merits and demerits of both configuration are duly discussed.

Self-Sensing Actuation With Adaptive Control in Applications With Switching Trajectory

This paper presents the application of self-sensing actuation (SSA) to facilitate the implementation of piezoelectric actuator in an intelligent mechatronic system. SSA is a technique to employ smart materials, such as piezoelectric materials, simultaneously as a sensor and an actuator; thereby increasing the level of integration of the system. The piezoelectric actuator is equipped with an exclusive adaptive controller amidst its nonlinearities and systems disturbance. The application area to be discussed is a microdispensing system, which is an example of a micromanufacturing process, combining a fluidic system and a positioning system.

Adaptive Control of Mechanical Systems Using Neural Networks

In this paper, we consider the decentralized adaptive control design problem for uncertain mechanical systems, where uncertainty may arise due to isolated subsystem and/or interconnections among subsystems. Radial basis function neural networks are used to approximate the nonlinear functions to include both dynamic and interconnection uncertainties in each subsystem. The stability of the thus designed control system can be guaranteed by a rigid proof. Finally, a simulation example is given to illustrate the effectiveness of the proposed algorithm.

Enhancing student involvement in a class using real-time response system

This paper presents the development of a real-time response system to enhance student involvement in a class; by means of addressing the attendance and the participation of students. The system consists of student pads on an Android mobile platform, a lecturer pad, and an Apache Tomcat server hosting the software of the system. The system allows the lecturer to keep track of the attendance of every student, as well as monitoring the comprehension of the class in relation to a subject via interactive multiple-choice-questions and short-answer-questions.

Ex Utero Harvest of Hematopoietic Stem Cells From Placenta/Umbilical Cord With an Automated Collection System

Hematopoietic stem cells (HSCs) from the human placenta and umbilical cord blood (UCB) provide a rich source of highly proliferative cells for many clinical uses with advantages over traditional sources like the bone marrow and periphery blood. However, the key current constraint with this source of HSCs is the inadequate number of HSCs cells that can be harvested in a single collection using current approaches, which render a large number of collections unusable on their own, even for pediatric patients. This paper will present the development of a device to enable more efficient harvesting of HSCs from placentas, which can be used ex utero, upon the discharge of placentas after deliveries. The device can be used to facilitate a two-fraction collection process. Results, in terms of mononucleated cells (MNCs) count, CD34+ cells count, as well as flow cytometry, will be furnished to verify the effectiveness of the developed system.

Intelligent compensation of friction, ripple, and hysteresis via a regulated chatter

In this paper, a hybrid control scheme utilizing a PID feedback control with an additional regulated chatter signal is developed to compensate motion impeding influences such as the effects due to friction, force ripples, and hysteresis in linear piezoelectric motor. The regulated chatter signal is a pulse sequence superimposed on the PID control signal. It has a fixed amplitude, and a pulse width regulated via iterative learning control. As such, the scheme is expected to be useful for applications involving iterative motion sequences. An analysis of the closed-loop performance is presented in the paper. Simulation and experimental results are also furnished to demonstrate that the proposed control scheme can reduce tracking errors significantly.

Microdispensing system via the contacting method.

This paper presents the development of a microdispensing system based on a contacting method, with an aim to lowering production and maintenance cost. The liquid, to be dispensed, is brought into contact with the work piece, thus dispensing a droplet by making use of the adhesion force between the liquid and the work piece. A piezoelectric actuator is employed as the drive for the system to achieve high precision. The control of the system is accomplished with a PID controller; controlling the dispensing process and trajectory tracking.

Trends in Motion Control

The trends in motion control will be expected to be primarily driven by developments in precision control and engineering, which has been steadily gathering momentum and attention over the last century. The driving force of this development arises from the requirements of miniaturization in products, where more functionality is to be contained in a smaller dimension, as well as the delicate processes to be able to realize them.

Servo Hydraulic and Pneumatic Drive

Among the various drives available, the hydraulic drive ranks at the forefront in terms of application history. The history of hydraulic power dated to the beginning of civilization, where artefacts show the applications of water turbines in power generation (Wikander, Handbook of Ancient Water Technology: Technology and Change in History, Brill, Leiden, 2000). However, more significant progress in this field is generally achieved following Pascal’s pioneering work which was later known as Pascal’s law of hydrostatic. Bernoulli’s discovery of the hydrodynamic law in 1750, and the Industrial Revolution in 1850 further catalysed the development of servo hydraulic drives. They led to the first applications of hydraulic equipment as a power source to power industrial machines such as the press, the crane, and the jack, as they also contributed to the development of hydraulic pumps, driven by steam engines, which produce hydraulic energy to run hydraulic systems. In the early 20th century, a revolutionary design of hydraulic drives used the oil, instead of water, as the hydraulic liquid, which greatly expanded the applications of hydraulic drives to more devices. World War II also contributed to the development of hydraulic drives, especially in the development of submarine control systems, radar/sonar drives, and military cargo transportation.

Development of a Portable Tissue Micro Array Instrument

Tissue micro array (TMA) is based on the idea of applying miniaturization and a high throughput approach to hybridization-based analyses of tissues. It facilitates biomedical research on a large scale in a single experiment; thus representing one of the most commonly used technologies in translational research. A critical analysis of the existing TMA instruments indicates that there are potential constraints in terms of portability, apart from costs and complexity. This paper will present the development of an affordable, configurable, and portable TMA instrument to allow an efficient collection of tissues, especially in instrument-to-tissue scenarios. The purely mechanical instrument requires no energy sources other than the user, is light weight, portable, and simple to use.