Embedded sensor

The design of smart materials and adaptive stmctures has required the development of constitutive equations that describe the temperature, stress, strain, and percentage of martensite volume transformation of a shape-memory alloy. These equations can be integrated with similar constitutive equations for composite materials to make possible the quantitative design of stmctures having embedded sensors and actuators for vibration control. The constitutive equations for one-dimensional systems as well as a three-dimensional representation have been developed (7). 

The basic components of a microhotplate-based sensor system are shown in the lower part of Fig. 2.1. They include the microhotplate and dedicated sensor electronics. As shown in Fig. 2.1 the electronics part may feature a temperature controller, read-out and measurement circuitry for the different sensor elements, or a first data processing stage. Another interesting feature is an embedded sensor interface. 

Embedded sensors Fiber optic sensors H2O, H2, 02, Signal is unaffected by electric fields, should minimally affect cell performance Currently an immature technology... 

The most commonly utilized embedded sensor for temperature distribution mapping is the thermocouple. Wilkinson et al.130 developed a simple, in-situ, and noninvasive method of measuring the temperature distribution of a fuel cell with micro-thermocouples. In this study, thermocouples were located in the landing area of the flow field plates (in contact with the GDL of the MEA) of a fuel cell. The temperature data taken at different locations along the flow channel was then used to find each temperature slope, which in turn were related through mathematical equations to the local current density of each location. Thus, the current density distribution in the fuel cell was determined by simple temperature measurements. The results of this approach are discussed in more detail in Section... 

Intrusion detection systems (IDS) are used as a computer network security tool and permit to alert an administrator in case of attack. The main goal of IDS is to detect and recognize network attacks in real time. Nowadays there exist different approaches for intrusion detection. It is signature analysis, rule-based method, embedded sensors, neural networks, artificial immune systems [1]—[6] and so on. The most of these IDS can detect the known attacks and have poor ability to detect new attacks. 

El-Sherif MA (2003) Smart textiles created with embedded sensors. MRS Bull Technol Adv 28 101-102... 

Protection system Deterministic control of functions and performance, including abihty to neutralize, heal, or shed threats Embedded sensors... 

Tamper-resistant, smart nanotags, self-powered covert sensor deployment, e.g., embedding sensors in consumer goods... 

In recent years great progress has been made in the development of embedded sensors and remote data acquisition. Some of the sensors are already well proven in the field, others are highly sophisticated research instruments and not (yet) used on a large scale. In this chapter sensor types are described that do not need any reference electrode to be embedded (essentially macrocell and resistivity sensors). 

Most of today s efforts aim at proving the feasibility of the basic concepts a great deal of work will have to be done before smart materials can be applied safely to aerospace structures. The effects of embedded sensors and actuators on the mechanical properties of structures, the long-term stability of the sensing system and its survival during processing are just the first matters which will require careful evaluation. 

Sensor (Machines), Fig. 6 Force curve measured by embedded sensor... 

In order to synchronize IS-sensor with other embedded sensors in system the time base and data evaluation time frame being used during system runtime have been streamlined by referring to Kinect sensor time base and taking the least common multiple of respective sensor evaluation time frames. 

There are many papers dealing with a solution of this problem. For many years a NIST (National Institute for Standards and Technology) conical transducer developed by Proctor [1982, 1986] out of a Standard Reference Material (SRM) and mass-backed (600 gr.) was used as a reference for AE measurements. Several new approaches have explored other transducer materials out of polyvinylidene fluoride (PVDF) or copolymers (Hamstad 1994 Hamstad and Fortunko 1005 Bar-Cohen et al. 1996 Hamstad 1997) as well as embedded sensors (Glaser et al. 1998). 

When we tamped the layered earth pressure box, we embedded the pvc pipe. When the tamped location came to 10 cm above the embedded sensor location. We picked out the pvc pipe and compacted the 2 cm fine sand from the bottom of the hole. We placed the numbered earth pressure box on the fine sand, we moved the earth pressure to and fro on the surface of the sand so that we made the earth pressure box contact with sand closely and made the backed soil compact. 

Active smart wearables which are able to react by sensing stimuli om the environment or the user through embedded sensors with the integration of actuators that act autonomously or by following orders from a base station ... 

Figure 14.4 Glass-laminated composite specimen with embedded sensors.

Figure 14.5 Glass-laminate composite specimen with embedded sensors, loaded on an Instron 1185 tester for a three-point bending test.

---