Document Type


Date of Award

Fall 1-31-2004

Degree Name

Master of Science in Mechanical Engineering - (M.S.)


Mechanical Engineering

First Advisor

Richard A. Foulds

Second Advisor

Zhiming Ji

Third Advisor

Rong-Yaw Chen


Tremor is a common movement disorder that occurs with specific neurological conditions. This condition may seriously impact daily living activities. The aim of the present study is to evaluate the possibility of the development of a wearable technology that is capable of exerting torques at a user's joints for suppressing tremor.

This thesis is based on the concept of "smart structures" which are made of Magneto-Rheological (MR) fluid that can dynamically alter its viscosity under magnetic field. The wearable tremor suppressing orthosis needs several conditions. It should be safe, light weight, simple and small in structure, and easily attachable. An MR fluid orthosis satisfies these conditions. This thesis shows the physical properties of MR fluid and the basic concept of a rotational MR fluid damper for suppressing tremor. Specifically, an MR fluid friction damper experimentally provides a damping coefficient capable of suppressing tremor. A simulation confirms that the damping moment of the MR fluid friction damper is sufficient to suppress that of the wrist tremor, with realistic peak to peak torque 0.022 Nm. This allows slower intentional movement to occur with only moderate attenuation.

The results of this work show that it is possible to design an MR fluid orthosis that is wearable and capable of suppressing tremors at the wrist. The proportionality of the tremor-reducing torque to electric current allows the potential for both user adjustment as well as automatic feedback control.