Inkjet Fabrication of Frame Dipole FSS

Digital fabrication techniques gives the possibility of producing elements with very thin and precise features which could allow the modification of UHF structures to reduce ink usage while still achieving similar performance. This paper investigates the case where dipole elements are modified into Frame Dipoles by removing areas where the surface current tends to be very low

Significant Factors in the Inkjet Manufacture of Frequency Selective Surfaces

Additive fabrication of electromagnetic structures by inkjet printing technology is both cost effective and compatible with a wide range environmentally-friendly substrates, enabling fabrication of frequency selective surface arrays with line dimensions less than 0.1 mm; difficult to achieve with conventional subtractive techniques. Several approaches have been investigated in order to produce low-cost frequency selective panels with acceptable level of isolation, such as savings in ink by depositing it at the edges of dipole elements where the surface current tends to maximize. The FSS transmission characteristics were improved by jetting multiple ink layers on the whole elements and at the edges. The electrical resistance of various arrays have been measured and analysed and has been used to assess the performances of the FSS

Inkjet printed paper based frequency selective surfaces and skin mounted RFID tags : the interrelation between silver nanoparticle ink, paper substrate and low temperature sintering technique Citation for published version (APA): Inkjet printed paper base

Inkjet printing of functional frequency selective surfaces (FSS) and radio frequency identification (RFID) tags on commercial paper substrates using silver nanoparticle inks sintered using low temperature thermal, plasma and photonic techniques is reported. Printed and sintered FSS devices demonstrate performances which achieve wireless communication requirements having a forward transmission scattering parameter, S 21 , depth greater than À20 dB at 13 GHz. Printed and plasma sintered RFID tags on transfer paper, which are capable of being mounted on skin, improved read distances compared to previously reported single layer transfer RFID tags fabricated by conventional thermal sintering

Sintering and applications of inkjetprinted silver nanoparticles

The presented thesis addresses the composition, inkjet-printing and low-temperature sintering of the currently predominantly used silver nanoparticle based inks and their application in flexible electronic devices. The concept of stabilization of silver nanoparticles in the ink by organic compounds like polymers or amphiphilic molecules requires the removal of these organics in order to introduce electrical conductivity of the patterns after printing and drying. To develop a manufacturing process that is compatible with thermo-sensitive substrate materials as well as the short processing times that are required for high-throughput manufacturing, several non-conventional sintering methods like plasma sintering and intense pulsed light sintering were investigated. For the improvement of ink formulations and sintering technologies, an exact understanding of the sintering mechanisms is of critical importance. On account of this requirement, the thermal sintering behavior of a silver nanoparticle ink was investigated in detail. Subsequently, the experimental results were used as input parameters for a sintering and resistivity model. Another focus of this thesis was the improvement of argon plasma sintering in terms of reduction of the technical complexity, substrate friendliness and processing time. For that purpose, the sintering of several silver nanoparticle inks via atmospheric pressure plasma devices was investigated. Eventually, the implementation of inkjet-printed and low temperature sintered silver patterns into flexible electronic applications was investigated by the manufacturing of a biochip platform as well as ultra-high frequency (UHF) electromagnetically active devices

Localized atmospheric plasma sintering of inkjet printed silver nanoparticles

Atmospheric pressure argon plasma sintering of silver nanoparticle inks was investigated to improve the plasma sintering process in terms of sintering speed, substrate friendliness and technical complexity. Sintering times were reduced to several seconds while achieving similar conductivity values of above 10% compared to bulk silver. Sintering can be carried out under ambient conditions at specific locations without exposing the entire substrate. Plasma sintering at atmospheric pressure exhibits the capability to be used in roll-to-roll production processes

UHF electromagnetic structures inkjet printed on temperature sensitive substrates: a comparative study of conductive inks and sintering methods to enable low cost manufacture

In this paper we demonstrate the use of inkjet printing as a facile digital fabrication tool for the cost effective manufacture of UHF RFID transfer tattoo tags and Frequency Selective Surfaces on low-cost flexible and porous substrates. Electrical and morphological properties of conductive features obtained from a range of metal nanoparticle inks and low temperature sintering methods, such as argon plasma and photonic flash, are evaluated. Large scale potential is addressed