Surface micromachined metallic microneedles

In this paper, a method for fabricating surface micromachined, hollow, metallic microneedles is described. Single microneedle and multiple microneedle arrays with process enabled features such as complex tip geometries, micro barbs, mechanical penetration stops and multiple fluid output ports were fabricated, packaged and characterized. The microneedles were fabricated using electroplated metals including palladium, palladium-cobalt alloys and nickel as structural materials. The microneedles were 200 mm-2.0 cm in length with a cross-section of 70-200 /spl mu/m in width and 75-120 /spl mu/m in height, with a wall thickness of 30-35 /spl mu/m. The microneedle arrays were typically 9.0 mm in width and 3.0 mm in height with between 3 and 17 needles per array. Using water as the fluid medium, the average inlet pressure was found to be 30.0 KPa for a flow rate of 1000 /spl mu/L/h and 106 KPa for a flow rate 4000 /spl mu/L/h.

[1]  Peter Enoksson,et al.  Micromachined electrodes for biopotential measurements , 2001 .

[2]  Richard M. White,et al.  Micromachined silicon needle for ultrasonic surgery , 1995, 1995 IEEE Ultrasonics Symposium. Proceedings. An International Symposium.

[3]  B. Bellhouse,et al.  Transdermal ballistic delivery of micro-particles: investigation into skin penetration , 2000, Proceedings of the 22nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (Cat. No.00CH37143).

[4]  W. H. Safranek The properties of electrodeposited metals and alloys , 1986 .

[5]  Ian Papautsky,et al.  Hollow Metallic Micromachined Needle Arrays , 2000 .

[6]  M. Allen,et al.  Micromachined needles for the transdermal delivery of drugs , 1998, Proceedings MEMS 98. IEEE. Eleventh Annual International Workshop on Micro Electro Mechanical Systems. An Investigation of Micro Structures, Sensors, Actuators, Machines and Systems (Cat. No.98CH36176.

[7]  Richard A. Normann,et al.  Micromachined, silicon based electrode arrays for electrical stimulation of or recording from cerebral cortex , 1991, [1991] Proceedings. IEEE Micro Electro Mechanical Systems.

[8]  Ian Papautsky,et al.  A low-temperature IC-compatible process for fabricating surface-micromachined metallic microchannels , 1998 .

[9]  Albert P. Pisano,et al.  Silicon-processed microneedles , 1999 .

[10]  Noel De Nevers Fluid mechanics for chemical engineers , 1980 .

[11]  Ian Papautsky,et al.  Fluid coupled metallic micromachined needle arrays , 1998, Proceedings of the 20th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. Vol.20 Biomedical Engineering Towards the Year 2000 and Beyond (Cat. No.98CH36286).

[12]  Richard M. White,et al.  Micromachined silicon ultrasonic atomizer , 1996, 1996 IEEE Ultrasonics Symposium. Proceedings.

[13]  K. Wise,et al.  A multichannel neural probe for selective chemical delivery at the cellular level , 1997, IEEE Transactions on Biomedical Engineering.

[14]  Silicon micromachined ultrasonic micro-cutter , 1994, 1994 Proceedings of IEEE Ultrasonics Symposium.