Embedded electronics for intelligent structures

Abstract

Intelligent structures with integrated control systems consisting of large numbers of distributed sensors, actuators, and processors have been proposed for the precision control of structures. This report examines the feasibility of physically embedding the electronic components of such systems. The hardware implications of functionality distribution are addressed, and it is shown that highly distributed systems can have substantially fewer communications lines and faster control loop speeds than conventional approaches, at the cost of embedding electronic circuit chips. A technique for the embedding procedure is presented which addresses electrical, mechanical, and chemical compatibility issues. Test specimens with functioning integrated circuits successfully embedded within graphite/epoxy composite laminates were subjected to static and cyclic mechanical loads, demonstrating nominal electrical function above normal design load limits. Operation of test specimens in a high temperature/humidity environement allowed the identification of a corrosive failure mode of the leads or lead-chip bonds. The application of a single-chip microcomputer to the control of a structural vibration problem demonstrates the potential for the development of monolithic integrated circuit devices capable of performing distributed processing tasks required for fully integrated intelligent structures.

Evaluation of the sensitivity and fatigue performance of embedded piezopolymer sensor systems in sandwich composite laminates

“…optics, shape memory alloys, strain sensors, and, more recently, the potential of creating a smart matrix system based on the use of nanoparticles. Lead zirconate titanate has attracted the greatest attention in a wide range of sensor forms and materials (Crawley and De Luis 1987, Warkentin and Crawley 1991, Chow and Graves 1992, Bronowicki et al 1996, Shukla and Vizzini 1996, Mall and Coleman 1998, Hansen and Vizzini 2000, Yocum et al 2003, and Tang et al 2011.…”

Use of piezoelectric as acoustic emission sensor for in situ monitoring of composite structures

“…So, it is important to study the effects of embedded sensors on the host composite materials. For example, Warkentin and Crawley [4] tested graphite/epoxy coupons with embedded integrated circuits on silicon chips. They showed a 15% decrease in ultimate strength of the host laminate with the embedded chips.…”

On Mechanical Properties of Composite Sandwich Structures With Embedded Piezoelectric Fiber Composite Sensors

“…These high stress concentration regions could serve as sites for the beginning of delamination and cracks, leading to premature structural failure of the component. Experimental studies have been conducted on the strength and failure of composite materials with embedded devices such as silicon chips, thermocouples, and fiber optic sensors, but a very limited research has been done on the embedded piezoelectric sensors [8][9][10][11][12][13][14][15][16][17]. The effects of embedded PZT (lead zirconate titanate) sensors on structural integrity of composites have been extensively studied and reported.…”