AAWSAP DIRD, Biosensors and BioMEMS: A Survey of the Present Field, March 2010

This Defense Intelligence Reference Document, dated 31 March 2010 and numbered DIA-08-1003-020, was prepared by the Defense Intelligence Agency's Defense Warning Office under its Advanced Aerospace Weapon System Applications Program. It surveys biosensors and biomedical microelectromechanical systems, covering brain-implanted micromachine neuroelectrodes, drug-delivery pumps, glucose sensors, neural interfaces, retinal prostheses, microfluidic lab chips, NASA cell-culture systems and microcantilever sensors. It concludes that the field is expanding rapidly, with nanomechanical systems expected to follow.

From the source:Release of 2026-09-18 Incident: 3/31/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD surveys biosensors and BioMEMS, a broad class of miniature biomedical devices that combine microscale engineering with sensing, fluid handling, stimulation, or drug-delivery functions. The report reviews major application areas including implantable blood-chemistry sensors, neural interfaces, neurostimulation, drug-delivery pumps, microfluidic systems, and emerging nanoscale extensions of the field, while emphasizing that miniaturization can improve sensitivity and enable functions that are difficult or impossible at larger scales. However, it also makes clear that practical development is constrained by biocompatibility, long-term stability, sensor drift, device degradation inside the body, and the high regulatory burden associated with implantable medical systems. The document presents BioMEMS as a rapidly growing and productive field whose future advances are likely to come through continued improvements in fabrication, materials, and reliability.

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released chemical energy warms the surrounding environment to a degree that
depends on the energy released in the exothermic reaction, which is characteristic of
the particular chemistry and the amount of reactants. The heating is then dependent on
the glucose concentration.
Figure 12 shows these devices. They are
made by MEMS techniques involving the •--·
processes of using patterning by
exposure to light through a mask
(photolithography), metal deposition by
evaporation, and sputter etching. The
result is the fabrication of sensors in
large arrays with many identical sensors
on a single substrate. The figure is a ·---photomicrograph of a part of a wafer
production run with nine identical
devices. Each one of the devices is less
than 1 mm in size and would be cut
apart and used independently. The
·--- ·--·darker rectangular areas at the top of ·•-
each device are the electrica l bonding
pads where wires attach to the device
to readout its electrical response.
Figure 13 shows the basic process in the Figure 12_ Photomicrograph 3 x 3 Array of
sensor operation. The sensor is planar Thermoelectric Glucose Sensors Constructed by
and composed of a layered structure Towe et al. at ASU
consisting of an enzyme gel and a
thermoelectric temperature sensor. Glucose from the local medium naturally diffuses to
the gel and the temperature sensor underlies a thin film of enzyme gel that conta ins
the glucose oxidase. A second enzyme called catalase is used to secondarily break
down hydrogen peroxide produced by the first reaction.
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