Biomedical Engineering Reference
In-Depth Information
and physical phenomena will become possible. With these small sensors and their ability
to approach the molecular level, we are beginning to regain our greatest senses: sight. As
science and technology have pushed to smaller and smaller scales, humans are no longer
able to rely on their most trusted sense (i.e., sight). However, with the advent of nanoscale
biosensors, and near-field optical sensing and imaging we are beginning to be able to visu-
alize phenomena previously unobserved. This is leading to a better understanding of why
particular events happen. One of the largest areas that will be impacted by the future of
these nanobiosensors is that of medicine.
Medical research and treatment has long been studied through a top-down approach, in
which physicians begin with the visual symptoms and trace their origin back to an
organ(s) and eventually a more detailed biological reason for the symptoms. Once the
symptoms are known, the standard treatment is prescribed. However, variability exists in
how effective these treatments are for the patient, due to the interrelated nature of biolog-
ical systems and the slight differences in these pathways from one individual to another.
With nanobiosensors and arrayed biochips, we will be able to obtain a much greater
understanding of systems biology and the interrelated nature of these pathways, by being
able to monitor them all simultaneously. This will lead to a true understanding of the best
means in which to treat a particular individual, fulfilling the ideal of personalized treat-
ment for everyone.
23.3
Mimicking Biology: Is This a Realistic Goal?
Felix T. Hong (personal communication, 2006) of Wayne State University has been an
active researcher in biosensing and bioelectronics for several decades and shares with us
his views on reverse-engineering biology and whether human-like intelligence can be real-
ized by artificial devices and products. Although the essay is inherently personal, he does
ask us to challenge our perceptions on what we mean by “smart” technology and the goal
of emulating biology.
The title of this volume “Smart Biosensor Technology” implies that the research and devel-
opment of a new generation of biosensors emphasizes “smart” features. Before we plunge
into a detailed discussion, we need to address the question of what constitutes smartness.
Contemporary sensors and digital computers are smart based on the nineteenth- or twenti-
eth-century standards and our contemporary expectations, but we expect them to be smarter
in the future. Thus, the pertinent issue here boils down to
in what ways biosensors can become
smarter than they have already been
. Perhaps a “smart sensor” ought to have some capability of
“comprehension” or those important features that distinguish the human brain from the most
advanced digital computers. One way to achieve this goal is to turn to biology for inspiration.
An earlier generation of information-technology professionals has already done just
that in a multidisciplinary effort known as molecular electronics (21-25) and biocomput-
ing (26-29). A frequently mentioned impetus for such endeavors was the continuing drive
for device miniaturization. The well-known Moore's law predicts an exponential increase
of the degree of miniaturization, in terms of chip densities and other related criteria.
Miniaturization could make the sensors smarter because the increasing computing speed
and the increasing number of computing elements would make it possible to perform
tasks, which had previously been considered unrealistic for digital computers. For exam-
ple, though still clumsy, character recognition, which requires a certain degree of analog-
pattern recognition, is no longer a pipe dream. However, “discrete” microelectronic
devices which operate on the basis of physical interactions will soon reach their physical
