This paper presents a flexible dual-type proximity sensor forrobotic applications such as human collaborative robots(HCRs) todetect the surroundings. The sensor consists of two parts; sensing transducer and a shielding layer. To amplify the sensing performance, a resonant frequency is formed by an inductive(L-type) electrode and two capacitive(C-type) electrodes, which are placed in coplanar with an LCR circuit. An optimal frequency range is suggested to amplify the proximity detecting performance with a consistent response of impedance change. The developed sensor has a size of 100 x120x2.8 mm³. To obtain the flexibility for various robot surfaces attachment, the electrode layer is made of Flexible Printed (a) Circuit Board(FPCB). Combined with the grounded shielding layer, the sensor can detect objects up to 300 mm in 10 mm resolution when attached to a grounded surface. The sensor is evaluated in diverse circumstances to validity for practical use on robotics.