Prof. Sidney Lang

Prof. Sidney Lang Profile

Professor Emeritus

Professor Emeritus

Department : Department of Chemical Engineering
Room : 207
59 - בנין הנדסת חומרים והנדסת כימיה ע"ש פוסטר
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Applications of pyroelectricity and piezoelectricity


  • Ph.D.: 1962, University of California at Berkeley; Professor 1976.

Research Interests

  • Properties and applications of piezoelectric, pyroelectric and ferroelectric materials. Electrical properties of biological materials. Measurement of biological parameters by means of piezoelectric and pyroelectric techniques. Editorial activities related to appointment as AssociateEditor of the journals Ferroelectrics, Ferroelectrics Letters.  Web Editor-in-Chief of the IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society (UFFC). Historian of the UFFC.

Research Projects

  • Development and application of the Laser Intensity Modulation Method (LIMM) for determination of polarization distributions in ferroelectricmaterials. Measurements of themal diffusivity of thin films. Study of calcite crystals in the pineal gland of the human brain. Use of piezo electric transducers for measurement of biological properties. Studies of the piezoelectric, pyroelectric, and ferroelectric properties of hydroxyapatite, a major component of human bone.

Research Abstract

  •  Laser Intensity Modulation Method (LIMM): Measurement of spatial distributionof polarization or space charge in bulk or in surface regions of ferroelectric single crystals, ceramics or polymers. Techniques developed which are now in use in more than seven different countries. The method is being extended at present to studies of glass-ceramics and of thin-film ceramic layers. Ferroelectricity and pyroelectricity in collagenous materials: Biological tissuesincluding bone and tendon exhibit piezoelec-tricity and pyroelectricity probably d e to the proteins of which they are partiallyor wholly composed. Studies are in progressto determine the molecular origin of the effects and their possible biologicals ignificance. Second harmonic generation used to show noncentrosymmetry and probable piezoelectric effect in crystals found in the pineal gland of the brain. Discovery of piezoelectric, pyroelectric and ferroelctric properties in hydroxyapatite, the principal mineral component of human and animal bone.