A PMMA Micro-suction Tool for Capsular Endoscope Using a Solid Chemical Propellant

This paper presents a PMMA (Poly (methyl methacrylate)) microsuction tool for capsular endoscope using a solid chemical propellant, AIBN (azobisisobutyronitrile). A capsular endoscope integrated with a micro-suction tool can gather the gastro-intestinal juice for medical diagnosis. Our previous PDMS (polydimethylsiloxane) micro-suction tool has a problem of structural layer detachment between glass substrate and PDMS Venturi-tube body. In this study, PMMA is used as a material to enhance the bonding strength, which in turn results in an improved suction efficiency. The bonding strength of the PMMA and PDMS micro-suction tool are measured to be 1.6 N/m and 0.3 N/m, respectively. The value is five times larger for the PMMA micro-suction tool than that of the PDMS micro-suction tool. Also, the minimum negative pressure for suction is measured. The PMMA micro-suction tool starts to pump the diluted ink when generated negative pressure is 0.11 kPa. The value is approximately three times lower than that of the PDMS micro-suction tool. The diluted ink of 1.57 μL is successfully pumped into the PMMA micro-suction tool reservoir.