SENSORS :: Specifications and Materials for Medical Sensors cont'd.

Substrates - All substrates are processed in sheet form only. This is done in order to maintain tight print-to-print and print-to-feature tolerances. Large substrate can be printed with images up to 23" x 31" (584 mm x 787 mm). CT prefers to use standard materials that we stabilize for our printing processes. However, for applications where special or customer-supplied materials are required, CT can help to evaluate their applicability to our manufacturing processes. Substrates that CT has used or is currently evaluating are:

Polyester	Clear or White	0.005" - 0.010" (0.13 mm - 0.25 mm)
Polycarbonate	Clear or White	0.005" - 0.020" (0.13 mm - 0.51 mm)
Polystyrene	Clear	0.015" - 0.070" (0.38 mm - 1.79 mm)

Ink - Conductive inks with which CT has familiarity include:

• Carbon
• Carbon/Silver Blend
• Silver
• Silver/Silver Chloride
• Metals and Metallized Carbons including Ag, Au, and Pt
• UV-Cured and Thermally-Cured Dielectric
• Specialty Materials including pressure-sensitive and UV-cured adhesives

Conductive Technologies will use ink specified by the customer for a particular application. In cases where conductive inks are not specified, CT will review and help in the recommendation of a material.

Metal Films - Sputtered metal films are available from several sources. Metal film with which CT has experience processing include Au, Ag, Ti, Pd, Pt, and Cu. These films can be obtained readily on substrates that are up to 0.25 mm in thickness. Metal film construction in terms of metal thickness depends on the application, but are typically in the range of 40 to 150 nm.

Reagents - CT has the ability to either print or deposit reagents onto printed elements. We prefer that our customers develop their own reagent system, however, CT can work with other outside agencies to help develop a reagent system. CT will work with our customers to determine reagent material specifications for optimal processing. Once a formulation has been identified, CT can manufacture the reagent mix in-house or have it built outside in conjunction with our sister company, Adhesives Research.