This study reports a new stacking method for assembling a 3-D microprobe array. To date, 3-D array structures have usually been assembled with vertical spacers, snap fasteners and a supporting platform. Such methods have achieved 3-D structures but suffer from complex assembly steps, vertical interconnection for 3-D signal transmission, low structure strength and large implantable opening. By applying the proposed stacking method, the previous techniques could be replaced by 2-D wire bonding. In this way, supporting platforms with slots and vertical spacers were no longer needed. Furthermore, ASIC chips can be substituted for the spacers in the stacked arrays to achieve system integration, design flexibility and volume usage efficiency. To avoid overflow of the adhesive fluid during assembly, an anti-overflow design which made use of capillary action force was applied in the stacking method as well. Moreover, presented stacking procedure consumes only 35 minutes in average for a 4 × 4 3-D microprobe array without requiring other specially made assembly tools. To summarize, the advantages of the proposed stacking method for 3-D array assembly include simplified assembly process, high structure strength, smaller opening area and integration ability with active circuits. This stacking assembly technique allows an alternative method to create 3-D structures from planar components.
References
[1]
Chcurel, M. Windows on the brain. Nature？2001, 412, 266–268, doi:10.1038/35085727. 11460129
[2]
Yao, Y.; Gulari, M.N.; Wiler, J.A.; Wise, K.D. A microassembled low-profile three-dimensional microelectrode array for neural prosthesis applications. J. Microelectromech. Syst？2007, 16, 977–988, doi:10.1109/JMEMS.2007.896712.
[3]
Frank, K.; Becker, M.C. Electrodes for extracelluar recording and stimulation. Phys. Techniques Biol. Res？1964, 5, 22–87.
[4]
Green, J.D. A simple microelectrode for recording from the central nervous system. Nature？1958, 182, 962, doi:10.1038/182962a0. 13590200
[5]
Wise, K.D.; Angell, J.B.; Starr, A. An integrated-circuit approach to extracellular microelectrodes. IEEE Trans. Biomed. Eng？1970, BME-17, 238–247, doi:10.1109/TBME.1970.4502738.
[6]
Najafi, K.; Wise, K.D.; Mochizuki, T. A high-yield IC-compatible multichannel recording array. IEEE Trans. Electron Dev？1985, 32, 1206–1211, doi:10.1109/T-ED.1985.22102.
[7]
Jones, K.E.; Campbell, P.K.; Normann, R.A. A glass silicon composite intracortical electrode array. Ann. Biomed. Eng？1992, 20, 423–437, doi:10.1007/BF02368134. 1510294
[8]
Mercanzini, A.; Cheung, K.; Buhl, D.L.; Boers, M.; Maillard, A.; Colin, P.; Bensadoun, J.C.; Bertsch, A.; Renaud, P. Demonstration of cortical recording using novel flexible polymer neural probes. Sens. Actuat. A？2008, 143, 90–96, doi:10.1016/j.sna.2007.07.027.
[9]
May, G.A.; Shamma, S.A.; White, R.L. Tantalum on sapphire micro-electrode array. IEEE Trans. Electron Dev？1979, 26, 1932–1939, doi:10.1109/T-ED.1979.19798.
[10]
Wise, K.D. Silicon microsystems for neuroscience and neural prostheses. IEEE Eng. Med. Biol. Mag？2005, 24, 22–29. 16248114
Takahashi, H.; Suzurikawa, J.; Nakao, M.; Mase, F.; Kaga, K. Easy-to-prepare assembly array of tungsten microelectrodes. IEEE Trans. Biomed. Eng？2005, 52, 952–956, doi:10.1109/TBME.2005.845224. 15887548
[29]
Adamson, A.W. Physical Chemistry of Surfaces, 5th ed ed.; John Wiley: New York, NY, USA, 1990.
[30]
Cheng, C.H.; Lin, H.H. Measurement of surface tension of epoxy resins used in dispensing process for manufacturing thin film transistor-liquid crystal displays. IEEE Trans. Adv. Pack？2008, 31, 100–106, doi:10.1109/TADVP.2007.901767.
