**Author details**

original publications [40, 56, 57], explored an integration technique in polyimide very similar to ours, with interconnect density motivations much akin to our own [58]. We have recently demonstrated a fully integrated parylene-based single-channel neural stimulator [59]. *In vitro* measurements demonstrated the ability to generate 7 V pulses of 500 µs pulse width from a wireless transmitter 4 mm away. Preliminary evidence from animal implantation studies has

BioMEMS, an emerging field in which MEMS are designed, fabricated, and utilized to interface with and examine biological systems, is a discipline replete with incredible possibilities, but also one that is fraught with potential pitfalls. This is no more true than in the case of implant‐ able microelectronics, where applications abound because of the near perfect match in the sizes of the functional components of the body, namely cells and neurons, and the technologies possible using microfabrication techniques. Materials must be carefully selected such that they are biocompatible with the body, while still enabling maximal functionality to be delivered to the patient, requirements that are often competing in nature. In this vein, the microtechnologies necessary for parylene-based flexible microelectrode technologies have been presented. All evidence thus far points to the fact that such parylene-based technologies are likely an ideal

It should be stressed that these technologies are not limited to use in retinal and spinal cord prostheses. In fact, the ability of our flexible arrays to conform to the geometries of interest in the human body enables them to be used in a variety of locations heretofore previously inaccessible with such high precision. Such locations include the surfaces of the cerebral cortex, another area of interest from both a scientific and treatment point of view due to such neuro‐ logical problems as stroke, epilepsy, and memory loss. Areas of other interest include periph‐ eral nerve and muscle. It is also possible to embed sensors in such arrays, as has recently been demonstrated [60], to assess mechanical forces placed on the tissues of interest by our arrays as well as to detect extrinsic pressures, such as those within the eye or within blood vessels.

Understandably, there is a public reticence to the implementation of such technologies in the human body. While such apprehension is not a recent phenomenon, the burgeoning era of computerized special effects in television and cinema has helped fuel the fear that the blending of "man" and "machine" can have devastating consequences. What is missed in such intima‐ tions is that, in the hands of ethical doctors, engineers, and other scientists, such consequences are extremely remote. But it is not about the inventors of these technologies, and it should never be about personal glory. All of that slips away the moment one talks to a person who has devoted their life to be a pioneer in the field by volunteering to be a test subject of such devices for the benefit of mankind. In such conversations, one realizes the full potential of this technology. Investigation into these devices not only has the possibility to positively affect the lives of such people, by enabling them to "walk" or "see" again, but it transcends all that by bringing about in all involved a sense of camaraderie. Indeed, the selfless motivation of such

shown these are mechanically reliable under surgical conditions.

34 Advances in Micro/Nano Electromechanical Systems and Fabrication Technologies

option for implantable neuroprostheses and microdevices.

**10. Conclusions and future work**

Damien C. Rodger1 , Wen Li2 , James D. Weiland1 , Mark S. Humayun1 and Yu-Chong Tai3

1 University of Southern California, Los Angeles, CA, USA

2 Michigan State University, East Lansing, MI, USA

3 California Institute of Technology, Pasadena, CA, USA
