A very simple and low-cost scheme is proposed for fabricating min-film transistors with poly-Si nanowire (NW) channels. In this scheme, the poly-Si NW channel is formed by cleverly employing the poly-Si sidewall spacer technique. In addition, the poly-Si NW channel is genuinely exposed to the environment after the poly-Si sidewall spacer formation in the new scheme. This unique feature, together with its simplicity and low-cost, makes this approach very suitable for applications and manufacturing of bio-logic sensing devices. Good device performance is demonstrated in this letter.