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Introduction to Biomimetics 35

Figure 1.21 Performing virtual reality tasks using the ERF-based MEMICA haptic interface offers the potential of
a highly attractive interactive simulation system.

without having to be present at the operation site. Telepresence requires the capability to intuitively
project to the user as much sensation of the remote site as possible, including the distribution of
reaction forces, temperatures, textures, and other sensations that we associate with our feeling of
touching objects. The potential of making such a capability was enabled with a high resolution and
large workspace using the novel remote MEchanical MIrroring using Controlled stiffness and
Actuators system (MEMICA) (Bar-Cohen, 1999; Fisch et al., 2003). For this purpose, scientists at
JPL and Rutgers University used an electro-rheological fluid (ERF), which becomes viscous under
electroactivation. Taking advantage of this property, they designed miniature electrically controlled
stiffness (ECS) elements and electrically controlled force and stiffness (ECFS) actuators. Using this
system,the feeling of the stiffness and forces appliedat remote or virtual environments arepotentially
reflected to the users via proportional changes in ERF viscosity. Figure 1.21 shows a graphic
representation of the concept of MEMICA for the simulation of various control procedures — either
through virtual reality or as a telepresence. Using such a system, surgeons may be able to conduct a
virtual surgery via a virtual reality display while ‘‘feeling’’ the stiffness and forces that are involved
with the procedure.
Potential beneficiary of the simulation of medical therapy includes astronauts who operate at a
great distance from Earth. The probability that an urgent medical procedure will need to be
performed in space is expected to increase with the growth in duration and distance of manned
missions. A major obstacle may arise as a result of the unavailability of on-board medical staff
capable of handling every possible medical emergency. To conduct emergency treatments and
deal with unpredictable health problems, the medical crews will need adequate tools, and the
capabilities to practice the necessary procedure in order to minimize risk to the astronauts. With
the aid of all-in-one type surgical tools and a simulator, astronaut(s) with medical background
would be able to practice the required procedures, and later physically perform the specific
procedures. Medical staff in space may be able to sharpen their professional skills by practic-
ing new procedures. Generally, such a capability can also serve people who live in rural and
other remote areas with no readily available full medical care capability. As an education tool
employing virtual reality, training paradigms can be changed while supporting the trend in
medical schools towards replacing cadavers with computerized models of human anatomy. Another
potential benefit that MEMICA offers is the ability to provide intuitive control of remote