His research has varied from photonic crystals and new fabrication techniques such as multi-beam interference lithography and colloidal self-assembly, complex fluids and soft condensed matter,[3] resulting in high citations of 1310, 771 and 537, two of them consistently published by Nature.
[4] His doctoral thesis An investigation of the fibrinogen to fibrin transition by means of light scattering was interdisciplinary, examining blood coagulation from viewpoints of both physics and medicine.
[6][4] Wiltzius worked at AT&T Bell Laboratories (later Lucent Technologies) from 1984 to 2001, rising to the position of director of semiconductor physics research.
[4] He has investigated the development of new fabrication techniques for photonic crystals[9] including colloidal self-assembly[10][11] and multi-beam interference lithography.
[12] He was also involved in developing plastic transistors on flexible substrates for various applications, including electronic paper.